JPH1053488A - Semiconductor liquid phase epitaxial growth method and apparatus, and wafer holder - Google Patents

Abstract

(57) [Problem] When a conventional method, apparatus, and holder are used, various problems such as deposition of polycrystal, nonuniform film thickness, and thermal deterioration of a substrate have occurred. SOLUTION: A wafer accommodating portion has a wafer accommodating portion for holding back surfaces of a pair of wafers 15 in contact with side walls so that the surfaces face each other at a predetermined interval, and an inlet 16 for injecting a source into the accommodating portion; And a holder cover 12 that covers an opening surface of the holder main body 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor liquid phase epitaxial growth method and apparatus for forming a semiconductor layer by epitaxial growth on a semiconductor wafer using a liquid source for epitaxial growth, and a method for accommodating and holding a wafer for epitaxial growth. Related to a wafer holder.

[0002]

2. Description of the Related Art In liquid phase epitaxial growth, a semiconductor material to be epitaxially grown is dissolved in a low-melting-point metal in a solvent as a solvent, and the source is brought into contact with a semiconductor wafer. This is a technique for epitaxially growing a semiconductor on a wafer. GaP (gallium phosphide), GaAs (gallium arsenide), AlGaAs using Ga (gallium) as a solvent
(Aluminum gallium arsenide) and epitaxial growth of compound semiconductors such as Ga (gallium) and Sn (tin)
Is used for epitaxial growth of Si (silicon) using as a solvent.

In principle, the liquid phase epitaxial growth method includes a step of bringing a source into contact with a wafer, a step of lowering the temperature of the source, and a step of detaching the source from the wafer if necessary. Various liquid phase epitaxial growth apparatuses and methods, such as a source injection method, a dipping method, and a slide boat method, are known depending on a method of bringing a source into or out of contact with a wafer.

In the source implantation method, a wafer is housed in, for example, a wafer holder and placed in an epitaxial growth chamber,
This is a method of performing epitaxial growth by injecting a source into an epitaxial growth chamber.

[0005] An example of a conventional apparatus and method using the source implantation method will be described with reference to FIG.

This epitaxial growth apparatus is usually called a boat, and is used in a horizontal or vertical furnace. The boat shown in FIG. 14 is used in a horizontal furnace,
(A) shows a state placed in a furnace before starting the epitaxial growth. However, furnaces and furnace tubes are omitted and not shown. The boat main part has a main body 5501, a source reservoir 5502, and a discharge source reservoir 5503.
A partition plate 5504 is provided between the discharge source reservoir 5503 and the discharge source reservoir 5503. In addition, wafer 550 is contained in main body 5501.
An epitaxial growth chamber 5506 is provided for accommodating 5 and performing epitaxial growth. The source reservoir 5502 and the partition plate 5504 are slidable in the horizontal direction, and can be moved during the epitaxial growth process by a quartz rod (not shown) usually inserted from outside the furnace into the furnace.

When performing epitaxial growth, FIG.
The wafer 5505 is placed in the epitaxial growth chamber 5506 as shown in FIG. The wafer 5505 is shown in FIG.
It is held vertically as shown in FIG. 4 or held horizontally or diagonally. In FIG. 14, a mechanism for holding a wafer such as a wafer holder is not shown. In the source reservoir 5502, the raw material of the epitaxial source is stored. The material of the epitaxial source is, for example, Ga
In the case of As epitaxial growth, a metal Ga serving as a solvent is used.
And epitaxially grown poly GaAs and Si
And the like.

In this state, the boat is introduced into the furnace and heated, and the source material is dissolved in metallic Ga and the source 5507 saturated with the epitaxial growth material is obtained. In order to obtain the source 5507, it generally takes a long time of one hour or more. When the source 5507 is obtained, FIG.
Slide the source reservoir 5502 to the left as shown in (b),
The hole 5081 provided in the source reservoir 5502 is
Set to 09. With this operation, the source 5507 flows into the epitaxial chamber 5506 through the source passage 5509, and comes into contact with the wafer 5505. Wafer 5
When the temperature is lowered in a state where the source 505 and the source 5507 are in contact with each other, the epitaxially grown raw material in the supersaturated source 5507 precipitates on the wafer and grows epitaxially.

When a desired amount of epitaxial growth is obtained, the partition plate 5504 is slid to the left as shown in FIG.
Outlet 508 provided in the epitaxial growth chamber 5506
Adjust to 3. With this operation, the used epitaxial source 5507 falls into the drain source reservoir 5503, and the epitaxial growth is completed.

An apparatus and a method for performing epitaxial growth of only one layer have been described with reference to FIG. 14. In general, in the source injection method, after a source used for epitaxial growth is discharged, a new source is injected to form a multilayer. Epitaxial growth can be performed.

FIG. 15 shows, as an example, an apparatus for performing two-layer epitaxial growth. The source reservoir 6602 is divided into right and left, and independent injection ports 6081 and 608 are respectively provided.
2 for accommodating the first source 6071 and the second source 6072, respectively. The source reservoir 6602 is slid to the right, the first source 6071 on the left is injected to perform the first epitaxial growth, and after the first epitaxial growth is completed, the first source is discharged, and then the source reservoir is discharged. Slide 6602 to the left and move to the second source 6 on the right
By implanting 072, epitaxial growth of two layers can be continuously performed.

The dipping method is a method in which a source reservoir containing a source material is placed in a heating furnace, the source material is melted by heating to form an epitaxial growth source, and a wafer is dipped therein. After that, the temperature of the heating furnace is lowered to perform epitaxial growth, and after epitaxial growth of a predetermined thickness is performed, the wafer is pulled up from the source to terminate the epitaxial growth.

The slide boat method is a method in which a wafer is held in a wafer holder, a slider containing a source is placed thereon, and when the temperature reaches a predetermined temperature, the slider is moved to bring the source into contact with the wafer to perform epitaxial growth. is there.

However, the conventional liquid phase epitaxial growth method has some problems in principle, and will be listed below in connection with the epitaxial growth method and the wafer holder for holding the wafer. (1) Polycrystalline deposition and non-uniform film thickness Liquid phase epitaxial growth is a method in which a supersaturated solute is deposited and grown on a wafer. To reach. The solute cannot reach the wafer from a source located away from the wafer, and precipitates as polycrystals in the source or on the wall surface of the boat.

Since the polycrystal grows non-uniformly, if it is deposited in the source near the epitaxial growth surface of the wafer or on the opposite surface or the periphery of the wafer, the epitaxial growth is hindered by the amount of the polycrystal deposited, and the unevenness of the epitaxial growth film thickness is reduced. cause.

In the implantation method, a source passage for guiding the source from the source reservoir to the epitaxial growth chamber is indispensable. However, polycrystal is deposited and adhered to the source passage, thereby preventing the inflow and outflow of the source. Such a phenomenon is particularly fatal when the source is replaced after the first semiconductor layer is grown to grow the second layer.

In the dipping method, precipitation of polycrystal on the outer edge and peripheral portion of the wafer poses a problem. When the epitaxial growth is simply performed by placing the wafer in the source, the solute of the source is naturally deposited on the back surface of the wafer, and the epitaxial growth is performed. To prevent this, see, for example,
As shown in FIG. 16 of JP-A-160092, a wafer 14 is placed in a shallow dish-like dish 13, a number of dishes are stacked and fixed with a cassette 15, which is placed in a source 12 to perform epitaxial growth. A method has been proposed.

In this method, since the back surface of the wafer is in close contact with the dish and does not contact the source, epitaxial growth on the back surface does not occur. Also, if a large number of dishes are used, epitaxial growth can be performed on many wafers at once.

On the other hand, since the epitaxial growth is performed while holding the wafer horizontally in the dish, after the predetermined epitaxial growth is completed, even if the wafer and the wafer holder are pulled out from the source, the source remains on the upper surface of the wafer and the epitaxial growth is promptly performed. Can not be terminated. As a result, it becomes difficult to control the thickness of the semiconductor layer, and the source remains non-uniformly, resulting in uneven thickness between wafers or within a wafer surface and a decrease in the flatness of the epitaxial growth surface.

In addition, a problem arises in that polycrystals are deposited on the bottom of the dish, which is the opposite surface of the wafer, and the thickness of the epitaxial growth layer becomes uneven.

On the other hand, as shown in FIG. 17 of JP-A-60-21897, a dipping method has been proposed in which the back surface of a wafer is brought into close contact with a spacer.

However, this method does not take into account diffusion of solute from the periphery of the wafer and precipitation at the edge of the wafer. FIG. 18 shows a state in which the wafer 1905 is dipped on the source 1907 and epitaxial growth is performed. Since the back surface of the wafer 1905 is in close contact with the spacer 1911, no growth occurs. However, as described above, in the liquid phase epitaxial growth, the solute in the source on the wafer surface diffuses and deposits on the wafer surface to cause epitaxial growth. As schematically shown in FIG. 18, in the central portion of the wafer 1905, only the source between the opposed wafers contributes to the growth. On the other hand, at the edge of the wafer 1905, the source around the wafer also contributes to the growth. As a result, the wafer 19
The edge portion of 05 grows epitaxially thicker than the central portion, and the in-plane uniformity of the thickness of the epitaxial growth layer deteriorates.

In general, since the edge portion of the wafer is chamfered, the crystal orientation is different from the surface, and the wafer is not flat. Therefore, abnormal growth such as polycrystal growth is likely to occur.

Further, in the dipping method, a solute precipitates in the source in the source reservoir, and the solute rises because it is lighter than the solvent Ga. Solutes, for example, polycrystalline GaAs, deposited in the source below the wafer holder during epitaxial growth adhere to the wafer holder and wafer in the source. Further, the solute that has emerged on the surface of the epitaxial growth source adheres to the upper portion of the wafer when the wafer is pulled up after the completion of the epitaxial growth.

As described above, the technique proposed in Japanese Patent Application Laid-Open No. Sho 60-21897 does not take measures against abnormal growth in the peripheral portion of the wafer, unevenness in epitaxial growth thickness, and solutes precipitated in the source. (2) Thermal Degradation of Wafer Since GaAs has a high vapor pressure of As, when exposed to high temperatures, As evaporates from the surface and the surface deteriorates. In order to prevent the evaporation of As, it is necessary to avoid placing the wafer at a high temperature for a long period of time, and to place the wafer in a narrow place as tightly as possible to increase the vapor pressure of As around the wafer to prevent evaporation. For example, in the heat treatment of a GaAs wafer, a silicon oxide film is formed on the surface of the wafer and As
For example, a method such as so-called cap annealing is employed to prevent evaporation of water.

However, in liquid phase epitaxial growth, the melting of the source material requires a high temperature equal to or higher than the epitaxial growth temperature and a long time, so that the wafer is exposed to the high temperature even during the preparation stage until the epitaxial growth becomes possible. In addition, since the epitaxial surface of the wafer needs to be brought into contact with the source, the wafer surface cannot be completely covered.

In the injection method, the wafer is held in a boat below the source and placed in a high temperature portion of the furnace together with the source material, so that the wafer is exposed to the high temperature for a long time. Further, since the source injection passage communicates with the epitaxial growth chamber where the wafer is placed, the wafer cannot be sealed in a narrow place.

In the dipping method, the wafer can be placed outside the heating furnace or in a low-temperature portion inside the furnace until preparation for epitaxial growth is completed. However, just before dipping, preheating is required to bring the wafer to the same temperature as the source, and thermal degradation during this time cannot be avoided.

The method of keeping the wafer in the low temperature section is as follows:
The growth of aP is disclosed in JP-A-60-115271. In this method, during preheating, the wafer is placed above the source liquid level in the source reservoir, and the wafer is sealed by closing the source reservoir.

However, the reason why the source reservoir is covered is to prevent evaporation of oxygen from the dopant source from the epitaxial growth source, and because the space in the source reservoir is large, it is insufficient to prevent thermal degradation of the wafer.

In this method in which the wafer is placed in a low-temperature part other than the furnace, the temperature gradient in the reaction tube where the substrate is placed sharply decreases from the part where the reaction tube goes out of the furnace. When the substrate is placed at a position outside the furnace, there is a problem that a large temperature distribution is generated in the plane of the substrate and stress is generated. Also,
When the wafer is lowered to the high temperature part in the furnace, there is a problem that thermal stress is generated due to a large temperature difference. When the stress is generated, warpage and crystal defects of the substrate are caused. (3) Non-uniform composition of epitaxial growth source For example, in liquid phase epitaxial growth of GaAs, metal Ga as a solvent and polyGaAs as an epitaxial growth material
s, and further, a dopant such as Si is put into the source reservoir, heated and dissolved to form an epitaxial growth source. However, it is difficult to obtain a uniform solution only by natural diffusion.
As, which is lighter than a, has a high concentration near the surface of the source and tends to become unsaturated at the bottom of the source. In addition, the epitaxial growth raw material to which a small amount such as a dopant is added,
There is a problem that unevenness is likely to occur in the source. This is because the epitaxial growth raw material is provided as a solid and cannot be uniformly arranged in the source reservoir.

As a countermeasure, it is conceivable to stir the sauce in the sauce reservoir. However, in a boat used in the above-mentioned horizontal furnace, it is necessary to perform stirring drive from the lateral direction, so that it is difficult to install a stirring device and a mechanism.

In the dipping method using a vertical furnace, it is relatively easy to install a stirring mechanism, but in the dipping method, the source saturation at the time of wafer dipping poses a problem. If the source is unsaturated, the problem that the wafer comes into contact with the source and dissolves at the same time occurs regardless of the epitaxial growth method. If the source is supersaturated, the deposited solute will cover the source surface. For this reason, there is a restriction that the source must not be supersaturated, particularly in the dipping method. (4) Residual and Incorporation of Epitaxial Growth Material In the case where two or more layers are continuously grown by the injection method, the first source is discharged and then the second source is injected. However, polycrystals are also deposited from the first source. In particular, in the source implantation method, such a phenomenon is more remarkable because a space such as a source passage in which a source originally unnecessary for epitaxial growth can enter is large. This deposit is not discharged even when the source is discharged, and remains in the boat body together with the source entangled with the deposit. Here, when the second source is implanted, the first source component is mixed into the second source.

For example, when AlGaAs is epitaxially grown following GaAs epitaxial growth, the GaAs source is mixed with the AlGaAs source, so that the Al mixed crystal ratio of the AlGaAs layer is reduced or non-uniform, and the dopant concentration cannot be controlled. There is a problem.

In the dipping method, a plurality of source reservoirs and sources are prepared, and wafers are sequentially placed therein to perform epitaxial growth. As shown in FIG. 17 in the above-mentioned JP-A-4-160092, since the wafer is housed in a dish-shaped wafer holder, it is difficult to discharge the source, and the source remaining on the wafer is mixed and the source composition is easily changed. It is difficult to obtain an epitaxially grown layer having a desired thickness and composition.

The present invention has been made in view of the above circumstances, and has been found to occur in conventional techniques, such as polycrystalline deposition, non-uniform film thickness, thermal degradation of a wafer, non-uniform composition of an epitaxial growth source, and residual and mixed epitaxial growth materials. It is an object of the present invention to propose a semiconductor liquid phase epitaxial growth method capable of solving various problems, an apparatus therefor, and a wafer holder used for performing epitaxial growth.

[0037]

A wafer holder according to the present invention has a wafer storage space for holding a back surface of at least one set of semiconductor wafers in contact with an inner side wall and holding the surfaces so as to face each other at a predetermined interval, A holder body provided with an inlet / outlet for injecting / ejecting a source into / from the wafer accommodating space, or an inlet for injecting a source into the wafer accommodating space and an outlet for ejecting the source from the wafer accommodating space; A holder cover that covers an opening surface of the holder body.

According to the present invention, there is provided an epitaxial growth apparatus comprising: a source reservoir for accommodating a source used for liquid phase epitaxial growth; an epitaxial growth chamber positioned below the source reservoir for accommodating a semiconductor wafer; A source passage provided therebetween,
And a front chamber provided in a part of the source passage, wherein when the source housed in the source reservoir is introduced into the epitaxial growth chamber through the source passage, the source is stirred in the front chamber. It is characterized by being done.

Another epitaxial growth apparatus of the present invention comprises:
A heating furnace having a high-temperature soaking region heated by the heating means to form a substantially uniform temperature distribution, and a low-temperature region located above the high-temperature soaking region and lower than the high-temperature soaking region; Gas supply means for supplying a reducing gas and / or an inert gas to the heating furnace; and a solute, which is provided in the high-temperature soaking region in the heating furnace and contains a semiconductor material used for epitaxial growth, dissolved in a solvent containing a metal. A source reservoir for storing the source, a wafer holder for holding a plurality of semiconductor wafers, and vertically moving the wafer holder in the heating furnace, and when performing epitaxial growth, the semiconductor wafer held by the wafer holder. Wafer holder moving means for immersing the source in the source reservoir, a stirring blade for stirring the source in the source reservoir, and the stirring blade It is moved in the vertical direction, characterized in that it comprises a stirring blade moving means for loading and unloading the stirring blade in the source.

According to the semiconductor liquid phase epitaxial growth method of the present invention, a step of holding a plurality of semiconductor wafers in a wafer holder, a step of accommodating the semiconductor wafers held in the wafer holder in an epitaxial growth chamber, Flowing a gas and / or an inert gas, heating the epitaxial growth chamber to a predetermined temperature, flowing a source housed in a source reservoir into a front chamber and stirring, and then stirring the epitaxial growth chamber. Introducing the source into the semiconductor wafer and bringing the source into contact with the semiconductor wafer, lowering the temperature in the epitaxial growth chamber, performing the epitaxial growth on the semiconductor wafer, and discharging the source in the epitaxial growth chamber to terminate the epitaxial growth. Process

According to the semiconductor liquid phase epitaxial growth method of the present invention, there are provided a step of holding a plurality of semiconductor wafers on a wafer holder, a high temperature soaking region where a heating means is used to form a substantially uniform temperature distribution, Holding the wafer holder holding a semiconductor wafer in the low-temperature region in a heating furnace having a low-temperature region located above the region and lower than the high-temperature soaking region;
A step of flowing a reducing gas and / or an inert gas into the heating furnace, a step of heating the high-temperature soaking region in the heating furnace by the heating means so as to have a predetermined temperature, and a step of: A step of lowering the temperature of the wafer holder and the semiconductor wafer to the predetermined temperature from the region to the position of the high-temperature soaking region, and moving the wafer holder and the semiconductor wafer downward to include a semiconductor material used for epitaxial growth. A step of placing the source in a source reservoir containing a source dissolved in a solvent containing a metal, and a step of lowering the temperature of the high-temperature soaking region to perform epitaxial growth on a semiconductor wafer; and Drawing out from the source and terminating the epitaxial growth.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (1) Wafer Holder According to First Embodiment FIG. 1 shows the structure of a wafer holder according to the present embodiment. FIG. 1A shows a structure B on the side of the wafer holder.
FIG. 1B is a longitudinal sectional view taken along the line AA showing the front structure, and FIG. 1C is a bottom view.

As shown in FIG. 1 (a), this wafer holder holds a plurality of wafers 15 alternately vertically or obliquely, and separates the back surfaces of the wafers by a wafer holder 14 so that the wafers 15 are separated. The structure is such that surfaces are held face to face with a space. Further, as shown in FIG. 1B, the wafer 15 is placed in a U-shaped pocket of the wafer holder main body 11, and is fixed by the cover 12 inserted into the pocket. The shape of the U-shaped pocket and the cover 12 conforms to the outer peripheral shape of the wafer, and the periphery of the wafer 15 is covered with the pocket and the cover 12. The cover 12 is inserted from the side when viewed in a furnace. As shown in FIGS. 1B and 1C, the wafer holder has a spout 13 at the bottom between the surfaces of the wafers 15 for injecting and discharging an epitaxial growth source. . Further, the upper slit 16 corresponds to a gas vent for injecting and discharging the source.

When the wafer holder according to the present embodiment is used in the dipping method, the wafer holder is pulled out of the source to terminate the epitaxial growth, and in the implantation method, the source is discharged from the epitaxial chamber to terminate the epitaxial growth. Is assumed. Therefore, the wafer is held vertically or obliquely so that the source can quickly flow off the wafer.
The outlet is provided at the lowermost part between the wafers.

The structure for holding the two wafers 15 back to back via the wafer holder 14 is also one of the features of the present embodiment. By bringing the back surface of the wafer 15 into close contact with the wafer holder 14, epitaxial growth on the back surface of the wafer, which tends to be a problem in the dipping method, can be prevented. In addition, by holding a plurality of wafers 15 in the wafer holder 14, the number of wafers that can be accommodated in the wafer holder increases, and as a result, the number of wafers that can be epitaxially grown at one time increases, so that productivity can be improved.

Another feature of the wafer holder is a structure in which the surfaces on which epitaxial growth is performed are held so as to face each other at a fixed interval. By keeping the epitaxial growth surfaces facing each other, polycrystalline precipitation does not occur on the facing surfaces,
An epitaxial growth layer having a uniform thickness and a flat surface can be obtained.

The fact that the present wafer holder can easily prevent the deposition of polycrystals and easily discharge the source is particularly effective when two or more layers are epitaxially grown by using the implantation method or the dipping method.

The distance between the epitaxial growth surface and the opposing surface of the wafer, that is, the thickness of the source on the wafer is an important factor for controlling the thickness of the epitaxial growth layer.
Since the solute in the source on the wafer surface diffuses and precipitates to the wafer surface to form an epitaxial growth layer, the thickness of the epitaxial growth layer is in principle proportional to the thickness of the source. It is more efficient to minimize the thickness of the source as much as possible without wasting the source. However, if the distance between the wafer and the opposing surface is set to a certain value or less, the source does not flow onto the wafer even when the wafer is put in the source, or the source does not flow down when the wafer is pulled up from the source, and the epitaxial growth starts. And the end can no longer be controlled. If the epitaxial growth surfaces of the wafer are opposed to each other, the required minimum source thickness is doubled, and the inflow and discharge of the source can be facilitated.

The specific distance between the wafers may be 0.3 mm or more, but more preferably 0.5 mm or more. Below 0.2 mm, the source may not enter between the wafers. When the thickness is 0.4 mm or less, when the wafer is pulled out from the source, the source may remain between the wafers due to the surface tension of the source.

Conversely, if the distance between the wafers is too wide, the solute in the source between the wafers cannot reach the wafer during epitaxial growth and precipitates in the source. In order to prevent such deposition, it is desirable that the wafer interval is 5 mm or less.

Since the diffusion of the solute depends on the time during which supersaturation is maintained, that is, the reciprocal of the cooling rate, the interval between wafers at which precipitation occurs also depends on the cooling rate. The following equation (1) is
It is obtained by an experiment, and it is desirable that the distance between the wafers is set in the range of the expression (1).

Wafer interval (mm) ≦ 3.1 × (1 / temperature reduction rate (° C./min)) ^1/2 (1) The wafer 15 is provided with a stepped portion 1 provided on the holder body 11.
7 is stored. A similar step is provided on the cover 12. The wafer 15 is housed on the side with the larger diameter of the step, and the diameter of this portion is made larger than the diameter of the wafer in consideration of the thermal expansion of the wafer. Since the opposite side of the step 15 from the back surface of the wafer 15 covers the edge of the wafer 15, the diameter of this portion is preferably smaller than the diameter of the wafer 15. This is to prevent the wafer from being detached from a predetermined position even if buoyancy is applied to the wafer in the source or a boat containing the wafer holder is moved.

However, if the diameter of this portion is too small, the area of the portion where epitaxial growth can be performed on the wafer surface is reduced, so that the diameter of the cover portion is preferably as large as possible.

Generally, since the periphery of the wafer is chamfered, the crystal orientation is different from the surface on which the epitaxial growth is performed, and an abnormality such as the growth of a polycrystalline semiconductor is likely to occur in the peripheral portion. For this reason, the peripheral portion is mechanically removed after the completion of the epitaxial growth, or the semiconductor element formed in the peripheral portion is removed, and the peripheral portion of the wafer is not substantially used. The unusable region varies depending on conditions such as the type and thickness of the epitaxial growth layer. However, since the bevel portion is 1 mm or less from the outermost periphery, it is general to remove 2 mm from the outermost periphery of the wafer for safety. Therefore, if the portion where the wafer holder contacts the wafer is limited to within 2 mm from the outermost periphery of the wafer, the loss of abnormal growth due to the wafer contacting the wafer holder can be substantially eliminated. That is, the diameter of the step portion 17 on the front surface side of the wafer is preferably equal to or more than a value obtained by subtracting 4 mm from the diameter of the wafer.

Alternatively, if the epitaxial growth is performed without bringing the source into contact with the chamfered portion of the wafer edge, the edge does not grow abnormally. Therefore, the step 1
It is desirable that 7 covers the edge chamfer.

In the dimension design of the wafer holder including the diameter, it is necessary to consider the difference in thermal expansion between the wafer holder and the wafer.

The wafer holder according to the present embodiment is also characterized in that the source is covered around the wafer so that the source does not enter the periphery or the side of the wafer, or the source is limited to a small amount.

The smaller the gap around the wafer, that is, the distance from the wafer edge to the wafer holder or cover, the more uniform the epitaxially grown film thickness. Conversely, if the gap is large and the solute that is the epitaxial growth raw material is larger than the distance that can be diffused in the source,
The epitaxially grown film thickness tends to be non-uniform. As described above, the diffusion distance depends on the temperature drop rate during epitaxial growth. The distance obtained by the experiment is half of the formula (1) when there are wafers on both sides, and the temperature drop rate is 0.1 ° C. /
4.9mm for minutes, 2.5m for 0.4 ° C / minute
m, 1.6 mm for 1 ° C./min. Therefore, the distance between the wafer edge and the wafer holder is desirably 4.9 mm or less.

If the gap between the wafer edge and the wafer holder is less than 0.5 mm, it is difficult for the source to enter the edge of the wafer. In order to absorb the difference in thermal expansion between the wafer and the wafer holder, the wafer holder desirably has a margin of less than 0.5 mm.

Another feature of the wafer holder according to the present embodiment is that, when the wafer holder is viewed in a furnace, the entrance of the pocket is provided in the lateral direction of the holder, and the wafer and the cover are inserted from the side. is there. A vertical force of buoyancy in an epitaxial growth source having a large own weight and a large specific gravity is applied to the wafer housed in the wafer holder. Then, by inserting the wafer and the cover from the side, the vertical movement can be reliably restricted by the holder body. (2) Wafer Holder According to Second Embodiment FIG. 2 shows the structure of a wafer holder according to a second embodiment of the present invention. 2A is a longitudinal sectional view taken along line BB showing a side structure of the wafer holder, FIG. 2B is a longitudinal sectional view taken along line AA showing the front structure, and FIG. It is a bottom view.

The structure, name, number, and operation of each part in this embodiment are basically the same as those in the second embodiment shown in FIG. 1, but differ in the following points.

In this embodiment, the wafer 15 is accommodated in the tapered portion 18 instead of the step portion in the space of the holder main body 11a. In the case of providing a stepped portion, a wafer holder must be prepared for each thickness of the wafer, but the tapered portion 18 can be accommodated even when the thickness of the wafer is different. Further, before the start of epitaxial growth, the wafer 15 is pressed against the lower taper by its own weight, and during the epitaxial growth, is pressed against the upper taper by buoyancy, so that the wafer 15 comes into close contact with the wafer holder 14a.
By manufacturing the wafer holder 14a from a material having good thermal conductivity such as carbon, the in-plane temperature distribution of the wafer 15 in close contact with the wafer holder 14a becomes constant, and uniform epitaxial growth can be performed.

For the same reason as in the first embodiment, the minimum diameter of the tapered portion 18 is preferably smaller than the diameter of the wafer and not less than 4 mm less than the diameter of the wafer, and the wafer is not chamfered. It is desirable that the diameter be equal to or larger than the diameter of the portion.

In the present embodiment, no gas vent is provided. However, the gas is not supplied to the holder body 11a and the cover 1
Since it is possible to move in and out of a gap such as between 2a, the source can be moved in and out by controlling the rate of injecting and discharging the source.

The source inlet / outlet 13a of this embodiment does not have an opening up to the back surface of the wafer 15 as in the first embodiment, and as shown in FIG.
Of the cross section of the wafer holder 14a, and forms a step with the wafer holder 14a to which the back surface of the wafer is in close contact.

FIG. 3 shows the positional relationship between the cross section of the wafer holder 14a, the wafer 15, and the injection port 13a. FIG.
(A) shows a wafer holder 1 as in the first embodiment.
The case where the height 4a and the outlet 13a are set at the same height is shown. In this case, since the source to be implanted hits the side surface of the wafer 15, the source may go around the back surface. It is important to limit the amount of the source entering the side surface of the wafer 15 or not to insert the source. However, in the structure shown in FIG. The source enters the outlet, and the outlet 13a
Solutes diffuse from the source. Therefore, the wafer 15
In the vicinity of the inlet / outlet 13a at the edge of the edge, the epitaxially grown film thickness increases.

FIG. 3B shows a structure in which the step of the injection port 13a is higher than the wafer holder 14a by the thickness of the wafer. In this case, the wafer 15 is stored in the step between the two. Since the source is injected into the front surface of the wafer, the source does not go around the back surface, and the epitaxial growth film thickness near the edge of the wafer 15 corresponding to the injection port 13a does not become uneven.

FIG. 3 (c) shows a case where the injection / ejection port 13a is higher than the wafer holder 14a by half the thickness of the wafer 15. Although this step has a height that is half the thickness of the wafer, the edge of the wafer 15 is rounded so that the source does not go around the back surface. The effect of making the edge epitaxially grown film thickness uniform is inferior to that of the structure shown in FIG. 3B, but it is easier for the source to enter and exit because the thickness of the injection port 13a is increased.

As described above, it is essential to provide a step so that the source does not come into contact with the injection port on the side surface of the wafer 15 when the wafer back surface is directly adhered without the wafer holder 14a. Becomes This is because if epitaxial growth is performed by bringing the source into contact with the side surface of the wafer while keeping the back surface of the wafer in close contact, the two wafers may be united due to growth on the side surface of the wafer. (3) Wafer Holder According to Third Embodiment FIGS. 4 and 5 show a wafer holder according to a third embodiment of the present invention. FIG. 4 shows a structure in which ten holder plates each including a holder plate 11b and a plug-in type cover 12b are combined. Pressing plates 19 are provided on both sides of the holder plate. FIG. 5 shows a sectional structure of each holder plate 11b and cover 12b, and a procedure for storing the wafer 15.

The wafer holder 11 b is
b, taper portion 1 for accommodating two wafers 15 on one side
8b. For the wafer diameter of 76.0 mm, the minimum diameter of the tapered portion 18b is set to 75.2 mm, the maximum diameter is set to 77.0 mm, and the taper angle is set to 45 degrees.
When a wafer 15 having a thickness of 0.35 mm is used, the distance between the opposed wafers is set to be 2 mm. The material of the holder body 14b is high-purity carbon.

As shown in FIG. 5 (a), the wafer 15 is inserted into the tapered portion 18b of the U-shaped groove of the holder plate 11b placed horizontally in a direction to expose the surface from the lateral direction. As shown in FIG. 5B, the cover 12b is inserted and the wafer 15 is fixed. The cover 12b is also provided with a similar tapered portion 18b. As shown in FIGS. 5C and 5D, the second wafer 15 is inserted into the tapered portion 18b downward from above. Next, as shown in FIG. 5 (e), after the next holder plate 11 is overlapped and another holder plate is similarly overlapped,
Finally, the holding plate 19 is overlaid. When the whole is set up, the two wafers 15 and 15 are stored with their front surfaces facing each other and their back surfaces facing the wafer holder 14b.

The fixing of the stacked wafer holders 14b is not shown in FIG.
A through hole may be provided in a portion other than the groove of 4b, and a pin or a screw may be inserted. Alternatively, a case large enough to accommodate a plurality of wafer holders may be prepared, and a holder plate may be placed in the case.

First, when a wafer is put after stacking the holder plates, the wafer is rotated at the time of storage because the groove is deep and the groove is thin, so that the orientation flat of the wafer, that is, the direction of the crystal orientation is fixed. Difficult to do. In this embodiment, the wafers are stored while being stacked on the holder plate, so that the orientation of the wafers can be easily adjusted. (4) Wafer Holder According to Fourth Embodiment FIG. 6 shows a wafer holder according to a fourth embodiment of the present invention. FIG. 6A shows the entire structure, and FIG.
Shows a vertical cross-sectional structure along the line CC.

The holder plate 11c according to the present embodiment has a semicircular groove having a tapered portion 18c in a peripheral region except for the opening surface side of the central circular holder holding plate 14c.
The cover 12c is also provided with a similar tapered groove 18c. The cover 12c is in a state where the holder holding plate 14c of the holder plate 11c fits into the groove existing between the tapers 18c and is fixed. The inlet / outlet port 13c and the gas vent groove 16c provided in the holder plate 11c have a step with respect to the holder holding plate 14c by the thickness of the wafer 15, as shown in FIG.

Here, the reason why the shape of the holder holding plate 14c is circular is that the direction of the wafer 15 can be easily adjusted when the wafer 15 is stored in the holder plate 11c.

The wafer holder according to the present embodiment has two
The wafers 15 are stored in the holder plate 11c, and the cover 1
2c can be attached, and one set in that state can be laminated or integrated in a case. Alternatively, only the plurality of holder plates 11c may be stacked and fixed, the wafer 15 may be stored in the holder plate 11c, and the cover 12c may be attached. In this case, the cover is one-to-one with the holder plate.
It is not necessary to employ a structure in which a cover that covers a plurality of holder plates is integrated. (5) Epitaxial Growth Method and Apparatus Thereof According to Fifth Embodiment Next, a source injection type liquid used in a horizontal furnace, which is more effective when using the wafer holder according to the first to fourth embodiments. A phase epitaxial growth boat, a liquid phase epitaxial growth method using the same, a dipping type apparatus using a vertical furnace, and a method therefor will be described. However, the following embodiment is not limited to the above-described wafer holder, and another type of wafer holder may be used.

FIG. 7 shows an epitaxial growth method according to the fifth embodiment step by step. In this embodiment, two layers of GaAs and AlGaAs are epitaxially grown on a GaAs wafer using the above-mentioned boat.

FIG. 7A shows a state where the wafer 10105 is placed in a furnace before starting the epitaxial growth. Here, furnaces, furnace tubes, and the like are omitted and not shown.

The main part of the boat has a main body 10101, a source reservoir 10102, and a drain source reservoir 10103.
A partition plate 101 is provided between the discharge source 101 and the drain source reservoir 10103.
04 is installed. Also, the wafer 10
An epitaxial chamber 10106 is provided for accommodating 105 and performing epitaxial growth. The main body 10101 is provided with a front chamber 10110, and the front chamber 10110 is connected to the epitaxial growth chamber 10106 by a source passage 10109. The control rod 101 is provided in the source passage 10109.
11 is inserted.

Source reservoir 10102, control rod 1011
1. The partition plate 10104 can be slid in the horizontal direction and can be moved during the epitaxial process by a quartz rod (not shown) inserted into the furnace from outside the furnace.

Before starting the epitaxial growth, FIG.
As shown in (a), a wafer 10105 is held in an epitaxial growth chamber 10106. The method of holding the wafer and the wafer holder are not particularly limited in the present embodiment. However, as shown in FIG. 7, the epitaxial growth surfaces of the two wafers are vertically held opposite to each other with a space therebetween. Is also good. Further, it is desirable that the entire periphery of the wafer is covered with a wafer holder, and only a space for accommodating only a minimum source required for epitaxial growth is secured.

In the source reservoir 10102, a raw material for an epitaxial growth source is placed. In the present embodiment, the source reservoir 10102 is divided into left and right, a first source 11071 for epitaxially growing GaAs is placed on the left side in the figure, and a second source 11072 for epitaxially growing AlGaAs is placed on the right side in the figure. ing. First
The source material may be, for example, 100 in metal Ga, 15 in polyGaAs, and 0.3 in dopant Si. The second source material is made of metal Ga of 100, poly G
aAs = 5.6, metal Al = 0.1, dopant Zn
May be set to 0.06.

In this state, the boat is placed in a furnace and heated to 950 ° C. in a hydrogen atmosphere to dissolve the source material. After about one hour, the temperature is reduced to 920 degrees Celsius and source implantation is started to begin epitaxial growth.

First, as shown in FIG.
02 is slid to the right to introduce the first source 11071 into the anterior chamber 10110.

As in the conventional apparatus, when there is no front chamber, the source flows directly from the source reservoir into the epitaxial chamber. For this reason, when the source composition is not uniform in the source reservoir, the source injected into the epitaxial growth chamber becomes non-uniform, for example, the source composition differs at the beginning and end of the implantation. In this embodiment, since the front chamber 10110 is provided, the sources are mixed when flowing into the front chamber 10110, and the whole becomes uniform. In addition, Ga
By keeping the mass of As, even if the dissolution in the source reservoir is insufficient and the source is unsaturated, the anterior chamber 10110
It becomes saturated within.

Next, as shown in FIG.
1 is slid to the right and injected into the epitaxial growth chamber 10106 through the source in the source passage 10109,
The wafer is brought into contact with the wafer 10105.

Next, as shown in FIG.
1 is the source passage 10109 on the left and the partition plate 10104
And return it to a position where it is not blocked. In this state, the epitaxial growth chamber 10106 is isolated from the source passage 10109.

Next, as shown in FIG.
104 to the right, the source outlet 11083
And the source remaining in the anterior chamber 10110 and / or the source passage 10109 are discharged into the drain source reservoir 101.
Discharge into the room on the left side of 03.

The temperature of the furnace was lowered in the state shown in FIG.
As epitaxial growth is performed. For example, the cooling rate may be 0.8 degrees Celsius / minute.

During the epitaxial growth, the epitaxial growth chamber 10106 is isolated from the source passage, and only the source required for epitaxial growth exists only on the epitaxial growth surface.
PolyGaAs is prevented from depositing and adhering to the wall surface of 106 and the like. Also, the source passage 10109 and / or the path of the second source in the anterior chamber 10110 are blocked by the control rods or the excess source is discharged, so that deposition of polyGaAs on the wall surface is prevented. You.
Therefore, when the first source is discharged, there is no residue of the deposit attached thereto or the source entangled with the deposit, so that mixing of the source can be avoided.

When the temperature drops to, for example, 830 degrees Celsius, the temperature is lowered from the temperature to the constant temperature, the epitaxial growth is stopped, and the control rod 10111 is slid rightward as shown in FIG. The drain source reservoir 101
Discharge to the left of 03.

Next, as shown in FIGS. 7 (g) to 7 (i), the second source is connected to the epitaxial growth chamber 1011.
Inject at 0. Except for sliding the source reservoir to the left, the procedure is similar to the first source injection shown in FIGS. 7 (b) -7 (d).

After the implantation, the temperature is lowered again in the state shown in FIG. 7 (i), and an AlGaAs layer is grown on the GaAs epitaxial growth layer. The temperature decreasing rate may be, for example, 0.8 degrees Celsius / minute.

When the temperature reaches, for example, 700 degrees Celsius, the control rod 10111 is slid to the right as shown in FIG. 7 (j) to discharge the second source to the right side of the drain source reservoir 10103, thereby completing the epitaxial growth process. I do.

First source 11 used for GaAs growth
071 and the second source 1 used for AlGaAs growth
Since 1072 is discharged to a partitioned portion of the source reservoir, each of them can be collected and used again by adding necessary epitaxial growth raw materials.

A comparison between the case where epitaxial growth is performed according to the present embodiment and the case where epitaxial growth is performed under the same conditions using the conventional boat shown in FIG. 14 will be described.

Of the wafers after the epitaxial growth, the one closest to the source injection port was cleaved vertically, and the thickness distribution of the wafer excluding the epitaxial growth layer was examined.

In the fifth embodiment and the conventional method, a wafer having a thickness of 350 ± 10 μm is used. In the conventional case, the lower edge is 42 μm with respect to the center.
(12%) It was thin. The lower edge is where the injected source first contacts. The source injected first is likely to be unsaturated at the source at the bottom of the source reservoir. Since the unsaturated portion of the source was implanted first, it is considered that the wafer was thinned as a result of etching at the time of implantation. In contrast, in the growth method according to the present embodiment, there was no difference in wafer thickness between the center and the edge, and the center at 2 μm within the wafer thickness tolerance was thick.

In order to examine the uniformity of the dopant, LEDs were manufactured using five wafers, and the emission wavelengths were compared.
Since a GaAs LED using Si as a dopant emits light between impurity levels, the emission wavelength depends on the Si concentration of the dopant.

The LED manufactured by epitaxial growth according to the present embodiment had an average wavelength of 938 nm, and the difference between the maximum and minimum was 4 nm. On the other hand, LE by the conventional method
D had the same average wavelength, but had a maximum-minimum difference of 11 nm.
And that the dopant was added non-uniformly.

The degree of mixing of the source was examined from the Al mixed crystal ratio of the AlGaAs layer epitaxially grown on the second source. The wafer on the left (upstream of the source implantation), the center, and the right (downstream of the source implantation) of the epitaxial growth chamber is cleaved, and A near the growth start interface of AlGaAs is cleaved.
The mixed crystal ratio was measured by photoluminescence. In the present embodiment, it was 0.30 as set, whereas in the conventional method, it was 0.28, 0.21, 0.11 lower than the set value from the left side.

The decrease in the Al mixed crystal ratio was caused by the first GaAs growth.
This shows that the source has been mixed into the second source for growing AlGaAs. In addition, the fact that the degree of reduction on the downstream side of the source injection in the conventional method is large indicates that when the second source is injected, it flows while absorbing the first source remaining in the source passage. . (6) Method and Apparatus for Epitaxial Growth According to Sixth Embodiment FIG. 8 shows an epitaxial growth apparatus according to the sixth embodiment. This apparatus comprises source passages 2091 and 2091 connecting source reservoir 2202 and epitaxial growth chamber 2206.
An anterior chamber 2210 is provided between 92. However, no control rod for shutting off between the front chamber 2210 and the epitaxial growth chamber 2206 is provided.

FIG. 8A shows a state before the epitaxial growth. An epitaxial growth source 2207 is accommodated in a source reservoir 2202. When performing epitaxial growth, slide the source reservoir 2202 to the left,
The source is injected into the epitaxial growth chamber 2206 via the front chamber 2210.

The source flows into the front chamber 2210 and temporarily stays there, but is homogenized by self-agitation due to the inflow. In order to lengthen the residence time and increase the stirring effect, it is preferable that the cross-sectional area of the source passages 2208 and 2091 in front of the front chamber 2210 be smaller than that of the source passage 2092 downstream of the front chamber 2210. (7) Epitaxial Growth Method and Apparatus According to Seventh Embodiment FIG. 9 shows the configuration of an apparatus according to the seventh embodiment. In this apparatus, a front chamber 3310 is provided on the surface of a boat body 3301, and the flow of the source from the front chamber 3310 to the epitaxial growth chamber 3306 is controlled by the movement of the source reservoir. Part 3023 of the bottom of source reservoir 3302 is
It reaches the bottom of 310.

FIG. 9A shows a state before the epitaxial growth. An epitaxial growth source 3307 is stored in the source reservoir 3302. When performing epitaxial growth, the source reservoir 3302 is slid to the left to bring it into the state shown in FIG. 9B. That is, the outlet 3308 of the source reservoir is opened to the front chamber 3301, and a part 3023 of the source reservoir blocks the outlet 3308 of the source reservoir and the source passage 3309. In this state, the source 3307
Flows into the front chamber 3310 and is homogenized by the agitation due to the inflow, but does not flow into the epitaxial growth chamber 3306. When the source reservoir is further slid to the left,
As shown in (c), the front chamber 3310 communicates with the source passage 3309, and the source is injected into the epitaxial growth chamber 3306.

In the sixth embodiment, since the source is injected into the front chamber and the injection from the front chamber into the epitaxial growth chamber is performed at the same time, the source may flow into the epitaxial growth chamber before the source is completely uniformized. . On the other hand, in the present embodiment, the timing of injecting the source from the front chamber 3310 into the epitaxial growth chamber 3306 can be freely controlled, so that epitaxial growth can be performed using a completely uniform source.

When the source reservoir 3302 is returned to the right from the state shown in FIG. 9B, the liquid level of the source moved to the front chamber 3301 rises. Front room 3310 and source passage 33
The source can be forcibly stirred by moving the source reservoir left and right while 09 is blocked by a part 3023 of the source reservoir.

In the case of GaAs epitaxial growth, a source material of an epitaxial growth source, for example, a GaAs single crystal is placed in the front chamber 3310 so that a saturated solution can be formed in the front chamber 3310 even if the source in the source reservoir is not saturated. it can. (8) Epitaxial Growth Method and Apparatus According to Eighth Embodiment FIG. 10 shows the configuration of an apparatus according to an eighth embodiment of the present invention. This device connects the first source 4071 and the second source 4072 to different source passages 4091 respectively.
And 4092.

The control rod 4411 shuts off the source passage 4092, and does not directly have a function of discharging the source remaining in the first source passage 4091 to prevent deposition and deposition from the first source. . However, by injecting the second source from a source passage different from that of the first source, it is possible to prevent the first source from being mixed. (9) Ninth Embodiment Epitaxial Growth Method and Apparatus Thereof The present embodiment relates to a semiconductor liquid phase epitaxial growth apparatus using a dipping method.

The basic configuration of this device is as shown in FIG. The apparatus includes a vertical heating furnace 101 having a high-temperature soaking section 102 and a low-temperature section 103 above it,
A gas supply system 104 for supplying a reducing gas, an inert gas, and a vacuum to the heating furnace 101; a wafer holder 105 for holding a plurality of wafers; a mechanism 106 for vertically moving the wafer holder; Source reservoir 107 installed in heat unit 102 and source 1 stored in source reservoir
08.

FIG. 11 shows a heater 109 as an example.
The configuration of a five-stage furnace having five is shown. However, the number of heaters is not limited, as long as the heaters 102 and 103 can be obtained. The low temperature section 103 is shown as a constant temperature area, but this section is the wafer holder 1
05 and the area for preheating and cooling the wafer,
For example, it may have a slight inclination as shown by a dotted line.

Japanese Patent Application Laid-Open No. 60-11571 discloses a method in which a wafer is kept in a low-temperature part outside a furnace. However, the temperature outside the furnace cannot be controlled by the furnace, and the temperature gradient is large. For this reason, thermal stress may be applied to the wafer and crystal defects may occur. Therefore, such a situation can be avoided by providing a low-temperature part capable of controlling the temperature in the furnace as in the present embodiment.

Here, when lowering the wafer from the low-temperature wafer standby position to the high-temperature epitaxial growth position, it is necessary to move the wafer at a certain speed or less in order to avoid a rapid temperature change. This speed is determined by the size of the wafer and the temperature gradient of the part where the wafer is moved. The smaller the wafer and the smaller the temperature gradient, the faster the wafer can be moved to the epitaxial growth position, resulting in the time required for the epitaxial growth process. Can be shortened.

Therefore, it is particularly important that the temperature of the wafer standby low-temperature portion is higher in view of the processing time, and that the temperature of the standby position is stable in view of the reproducibility of production.

Since the temperature outside the furnace is not stable because it is directly affected by the outside air, it is desirable to have a controlled low temperature part in the furnace. As evaporation from the substrate becomes remarkable from around 700 ° C., controlling the temperature of the low-temperature part to 500 to 600 ° C. can minimize the process time while avoiding thermal deterioration of the substrate.

FIG. 11 shows two source reservoirs 107 placed on the source reservoir 113. The source reservoir 107 is rotated by the drive mechanism 114, and can move an arbitrary source reservoir directly below the wafer holder. One of the features of the present embodiment is that a plurality of source reservoirs are provided and a mechanism for moving an arbitrary source reservoir to a position immediately below the wafer holder is provided.

With this configuration, the epitaxial growth can be performed using a plurality of sources since the wafer can be placed in an arbitrary source and epitaxial growth can be performed, so that a plurality of epitaxial growth layers can be obtained. Driving the source reservoir is not limited to rotational movement,
It may be a linear motion or the like, as long as it can move a plurality of source reservoirs directly below the wafer holder.

The drive mechanism 114 is also provided with a vertical drive mechanism, so that the source 108 can be taken out from below the heating furnace 101.

Another feature of the present embodiment is that a mechanism for stirring the sauce is provided. FIG. 11 shows the stirring blade 115 lowered into the sauce 108 and the stirring blade driving mechanism 116. By rotating the stirring blade 116, the sauce can be stirred. The stirring is not limited to the rotation, but may be a vertical movement, a horizontal movement, or a combination thereof. The shape of the stirring blade can be any shape such as a plate shape or a propeller shape that matches the movement of the blade. Alternatively, without being limited to the shape of the blade, an object having a predetermined volume may be taken in and out of the sauce using vertical movement, and the liquid level of the sauce may be moved up and down for stirring.

Another feature of the present embodiment is that a structure is provided in which a solute semiconductor material is supplied to a source and saturated at a high temperature at which epitaxial growth is performed. FIG. 11 shows the specific mechanism as the semiconductor material 1
17 and a mechanism 118 for driving it up and down. However,
In FIG. 11, a mechanism for holding the semiconductor material 117 is omitted.

By stirring and supplying the sauce using the apparatus according to the present embodiment, the following effects can be obtained.

In order to perform liquid phase epitaxial growth, it is necessary that the source is saturated when the wafer is put into the source. If the source is unsaturated, the wafer will melt into the source when the wafer is placed in the source. Conversely, when the substrate is supersaturated, solutes deposited before the wafer is placed cover the source surface, and particularly in the dipping method, it becomes an obstacle when the wafer is placed in the source. For this reason, it is calculated that the source is saturated with the solute semiconductor material at the temperature at which epitaxial growth starts, and a predetermined solvent metal and solute are put into the source reservoir at room temperature and the temperature is raised. However, the source becomes unsaturated or oversaturated at the start of epitaxial growth due to undissolved solute, error in temperature control, error between the calculated solubility and the actual value, and the like.

In liquid phase epitaxial growth, the solute floats on the surface of the solvent because the metal solute has a higher specific gravity. For this reason, in order to dissolve all the solutes in the solvent, the solutes need to diffuse into the solvent, which takes a long time. In addition, a concentration difference easily occurs between the vicinity of the surface of the source and the inside thereof. By stirring the source according to the above-described embodiment, the movement of the solute is promoted, the solute is prevented from remaining undissolved, and the source is made uniform. This has the effect of reducing the time it takes to complete.

The source supply mechanism has an effect of preventing solute precipitation before epitaxial growth due to supersaturation. An amount of solute that is surely unsaturated at the temperature at which epitaxial growth starts is added to the solvent at room temperature in advance, and the temperature is raised to the epitaxial growth start temperature. Can be dissolved in the solute until the solute is saturated. By performing such an operation at a constant temperature or while increasing the temperature, it is possible to prevent the source from becoming supersaturated and the solute from being precipitated on the surface. It is desirable that the temperature at the end of the solute supply is equal to the epitaxial growth start temperature so that precipitation does not occur after the supply of the solute and before the start of epitaxial growth.

The supply of the solute to the source can be completed in a short time by stirring the source. Further, it is desirable to attach a solute semiconductor material to the stirring blade, or to make the stirring blade itself or a part thereof from a solute semiconductor material. For example, in the case of GaAs epitaxial growth using a Ga solvent, a stirring mechanism and a source saturation supply can be used as mechanisms by using GaAs stirring blades.

In this apparatus, after one epitaxial growth, the wafer is removed from the wafer holder, a new wafer is mounted on the wafer holder, and the epitaxial growth can be repeated using the source as it is. The source supply mechanism can be used to supply the consumed solute before the second and subsequent epitaxial growths.

When performing the first epitaxial growth,
The liquid level of the source rises by dipping the wafer holder into the source, and when epitaxial growth is performed in this state, polycrystals are deposited on the wall surface of the source reservoir to a position higher than the normal source liquid level. In this case, as described above, by adopting a method in which the stirring object is taken in and out of the source and stirred, the precipitate at a high position is immersed in the source, and the precipitate can be dissolved and reused. .

Next, the infrared light L having the structure shown in FIG.
In order to manufacture epitaxial growth wafers for ED,
The structure and growth method of a specific apparatus for obtaining a GaAs epitaxial growth layer doped with Ga using GaAs and Si as solutes using Ga as a source solvent and using the above apparatus shown in FIG. 11 will be described. .

The heating furnace 101 is a vertical 5-stage heater furnace. The length of the furnace body is 150 cm, and the inner diameter of the quartz reaction tube installed in the furnace is 30 cm. The high temperature soaking section 102 has a length of 30 cm within a range of ± 0.5 degrees Celsius, and the temperature of the low temperature section 103 when the high temperature soaking section is heated to 1000 degrees Celsius is 3
It has a slope of 482 degrees Celsius to 514 degrees Celsius in the range of 0 cm.

The source reservoir 113 is made of quartz having a diameter of 28 cm, and its drive shaft is a quartz tube having a diameter of 12 cm.
The drive mechanism 114 rotates the source reservoir 113 by 180 degrees.

As shown in FIG. 13, the source reservoir 107 has a structure in which two source reservoirs 1071 and 1072 are integrated. The source reservoir 107 is made of carbon and has a width of 17.5 c so that a diagonal line is about 28 cm.
m, a depth of 21.9 cm, and a height of 20 cm. This cuboid has a width of 8cm and a depth of 20.9c
Two rectangular holes each having a depth of 19 cm and a depth of 19 cm are provided. These two holes serve as a first source reservoir 1071 and a second source reservoir 1072. The wall thickness between the outer wall of the source reservoir and the source reservoir is 0.5 cm, and the bottom thickness is 1 cm.

The stirring blade 115 has a width of 5.6 cm and a length of 8 cm.
cm, a quartz plate having a thickness of 0.8 cm, and a rod for driving the blade is a quartz rod having a diameter of 1.4 cm. Drive mechanism 116
Is to rotate a stirring blade through a quartz rod and move it up and down.

The semiconductor material 117 is a disk-shaped GaAs single crystal having a diameter of 5 cm and a thickness of 2.4 cm.
4 cm quartz rod. The drive mechanism 118 can move the GaAs disk up and down via a quartz rod and further rotate it.

The gas system 104 contains hydrogen,
Nitrogen and a mixed gas of both are supplied and a vacuum is drawn.

The wafer holder 105 is made of carbon and has the structure shown in FIG. 2 in which the holder plates 14c shown in FIG. 6 are stacked. The material of the wafer holder needs to have thermal resistance and chemical resistance to the epitaxial growth source, and is preferably a material that can be processed with high precision. Further, a base material whose surface is coated with another material may be used. Specifically, in addition to carbon, quartz, silicon carbide, sapphire, other ceramics and the like can be mentioned.

Next, the result of forming an epitaxial growth layer based on the above embodiment will be described.

The first source reservoir was for GaAs epitaxial growth, and contained 7500 g of metal Ga as a solvent, 1197 g of polycrystalline GaAs as a solute, and 22.5 g of silicon pieces. The second source reservoir is for AlGaAs epitaxial growth, and includes 7500 g of metal Ga as a solvent, 238.1 g of polycrystalline GaAs as a solute,
36.7 g of Al wire was placed.

49 holder plates are stacked, housed in a box-shaped cassette and integrated to form a wafer holder, having a diameter of 62 m.
After 98 sheets of m-type and 300 μm-thick Si-doped N-type GaAs wafers were mounted on the respective holder plates and the covers were attached, the wafer holder was held at a low temperature in the heating furnace.
Further, the conductive material 117 and the stirring blade 115 were placed in the low temperature section.

The position of the source reservoir 113 was adjusted so that the first source reservoir was directly below the stirring blade and the semiconductor material.

In this state, the inside of the furnace was once evacuated, and then the inside of the furnace was filled with hydrogen. After the inside pressure became normal, 5 liters of hydrogen per minute was continuously flowed.

At the same time as the normal pressure, the temperature of the furnace was started, and after 2 hours, the temperature reached 915 ° C. at which the epitaxial growth was started.

The GaAs epitaxial growth source in the first source reservoir has a calculated 30 g of Ga at 915 degrees Celsius.
As is unsaturated. Upon reaching 915 degrees Celsius, the semiconductor material 117 was lowered into the GaAs epitaxial growth source 108 in the first source reservoir and spun at a rate of 15 times per minute for 30 minutes. In this step, GaAs and Si initially placed in the source reservoir were completely dissolved, and after the epitaxial growth was completed, the weight of the semiconductor material 117 was measured. As a result, 32.5 g had melted into the source.

After stirring for 30 minutes, the semiconductor material 117 was lifted up, and the source reservoir 113 was rotated half a turn. By this rotation, the GaAs epitaxial growth source reservoir was placed at a position directly below the wafer holder 105, and the AlGaAs epitaxial growth source reservoir was placed at a position directly below the stirring blade 115.

Next, the wafer holder was lowered in the source reservoir to a position where it did not come into contact with the source liquid level, and was kept there for 10 minutes. This location is inside the isotropy, and the temperature of the wafer and the source are almost the same.

After 10 minutes, the wafer holder was lowered into the source, the temperature was lowered at a rate of 0.4 ° C./min to start epitaxial growth, and the wafer holder was pulled up at 860 ° C. to complete the epitaxial growth.

During this time, GaAs grows epitaxially on the wafer. Since Si as a dopant is spontaneously inverted, an N-type GaAs epitaxial growth layer grows in the first half of the epitaxial growth, and a P-type GaAs epitaxial growth layer grows in the latter half of the inversion temperature of about 880 ° C. or lower.

During the GaAs epitaxial growth, the stirring blade 115 is placed underneath the AlGaAs in the second source reservoir.
It was lowered into the s epitaxial growth source and rotated at a rate of 15 times per minute to completely dissolve the source solutes AlGaAs and Al.

At the same time that the GaAs epitaxial growth was completed at 860 ° C., the temperature was maintained at 860 ° C.
The stirring blade 115 and the wafer holder 105 were lifted from the respective source reservoirs, and the source reservoir 113 was rotated again by a half turn to exchange the positions of the source reservoirs.

[0149] During the source exchange, the wafer holder was moved out of the source reservoir, but was kept in the soaking zone in the furnace. The reason why the wafer holder is not pulled out of the furnace or to a low temperature part in the furnace is to keep the wafer holder at the same temperature as the source, to omit preheating before the next epitaxial growth starts, and to simplify and speed up the epitaxial growth process. is there. By using a wafer holder having a high degree of sealing like the wafer holder according to the above-described embodiment, thermal deterioration can be avoided even when the wafer is held at a high temperature.

Subsequently, the wafer holder was dipped in the source of the second source reservoir, and AlGaAs epitaxial growth was performed.

The temperature of the source was lowered at a rate of 0.4 degrees Celsius per minute, and the temperature of the wafer holder was raised to a low temperature at 820 degrees Celsius to complete the epitaxial growth.

In this step, an AlGaAs epitaxial growth layer was grown on the GaAs epitaxial growth layer.

After the completion of the epitaxial growth, the temperature of the furnace was lowered, and when the temperature of the low temperature section fell below 200 ° C., the inside of the furnace was replaced with nitrogen, and the wafer holder and the wafer were taken out.

The structure of the wafer obtained in the above steps is as shown in FIG. N-type GaAs wafer 91
A 60 μm thick N-type GaAs epitaxial growth layer 92.40 μm P-type GaAs epitaxial growth layer 9
A 3.10 μm non-doped AlGaAs layer (Al composition ratio 0.7) 94 is grown. The surface after the epitaxial growth was smooth.

When this wafer is etched with hydrofluoric acid at 50 degrees Celsius, only the AlGaAs layer 94 is etched. Etching was performed to obtain an epitaxially grown wafer having the structure shown in FIG.

Out of 98 wafers having the structure shown in FIG. 12B, every third wafer is cleaved and 25 pieces of GaAs are stained by stain etching.
The s epitaxial growth layer was examined. The N-type GaAs layer has an average thickness of 58.4 μm, a standard deviation of 4.2 μm, and a P-type GaAs layer.
The aAs layer has an average thickness of 38.8 μm and a standard deviation of 2.9.
μm.

The average thickness coincided with the design values of 60 μm and 40 μm, and the standard deviation was remarkably improved as compared with the conventional epitaxial growth method in which the film thickness accuracy was around ± 30%.

As described above, Si-doped GaAs containing Ga as a solute
s and undoped AlGaAs have been described as an example, but GaAs, A
The present invention can also be applied to liquid phase epitaxial growth of lGaAs, GaP, and other compound semiconductors, and further to liquid phase epitaxial growth of Si using Sn or Ga as a solvent.

[0159]

As described above, the wafer holder of the present invention holds the wafer face-to-face and covers the periphery of the wafer to limit the presence of unnecessary epitaxial growth sources around the wafer, thereby enabling the polycrystal in the epitaxial growth apparatus to be formed. Precipitation can be prevented, diffusion of the source solute from the periphery of the wafer to the edge of the wafer can be suppressed, and an epitaxially grown layer having a uniform thickness and composition can be obtained.

Also, the epitaxial growth apparatus of the present invention
By uniformizing the epitaxial growth source and preventing unnecessary sources and polycrystals from being left in the path for supplying the source to the wafer holder, uniform and controllable, especially when performing liquid phase epitaxial growth of two or more layers. An epitaxially grown layer with good quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view and a bottom view showing a configuration of a wafer holder according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view and a bottom view showing a configuration of a wafer holder according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a positional relationship between a wafer and a spout in the wafer holder.

FIG. 4 is a perspective view showing a configuration of a wafer holder according to a third embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a procedure for accommodating a wafer using the wafer holder for each process.

FIG. 6 is a perspective view and a longitudinal sectional view showing a configuration of a wafer holder according to a fourth embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing an epitaxial growth method and an epitaxial growth method according to a fifth embodiment of the present invention.

FIG. 8 is a longitudinal sectional view showing an epitaxial growth method and an epitaxial growth method according to a sixth embodiment of the present invention.

FIG. 9 is a vertical sectional view showing an epitaxial growth method and an apparatus therefor according to a seventh embodiment of the present invention.

FIG. 10 is a longitudinal sectional view showing an epitaxial growth method and an epitaxial growth method according to an eighth embodiment of the present invention.

FIG. 11 is a longitudinal sectional view showing an epitaxial growth method and apparatus according to a ninth embodiment of the present invention.

FIG. 12 is a longitudinal sectional view showing a configuration of a wafer obtained by the epitaxial growth method.

FIG. 13 is a longitudinal sectional view showing a configuration of a source reservoir in the epitaxial growth apparatus.

FIG. 14 is a longitudinal sectional view showing a configuration of a conventional epitaxial growth apparatus.

FIG. 15 is a longitudinal sectional view showing the configuration of another conventional epitaxial growth apparatus.

FIG. 16 is a longitudinal sectional view showing a conventional epitaxial growth method using a dipping method.

FIG. 17 is a longitudinal sectional view showing another conventional epitaxial growth method using a dipping method.

FIG. 18 is a longitudinal sectional view showing a positional relationship between a wafer and a source when epitaxial growth is performed by a conventional epitaxial growth method.

[Explanation of symbols]

11, 11a, 11b, 11c Wafer holder 12, 12a, 12b, 12c Cover 13 Injection port 14, 14a, 14b, 14c Wafer holder section 15, 105, 10105, 5505 Wafer 16 Gas vent 17 Step section 18 Taper section 19 Pressing plate 91 N-type GaAs wafer 92 N-type GaAs epitaxial growth layer 93 P-type GaAs epitaxial growth layer 94 Non-doped AlGaAs layer 101 Heating furnace 102 High-temperature soaking unit 103 Low-temperature unit 104 Gas supply system 105 Wafer holder 106 Vertical drive mechanism 107 Source reservoir 1071 First One source reservoir 1072 Second source reservoir 108 Source 109 Heater 110 Wafer 111 Spacer 112 Groove 113 Source reservoir 114 Drive mechanism 115 Stirrer blade 116 Stirrer blade drive mechanism 117 Semiconductor material 118 Driving mechanism 1081 to 1085, 2208, 3308, 5081
5085, 6081, 6082 Source outlet 1109, 2091, 2092, 3309, 4409,
4091, 4092, 5509 Source passage 1110, 3310 Front chamber 1111, 4411 Control rod 10101, 3301, 5501 Main body 10102, 2202, 3302, 3023, 550
2,6602 source reservoir 10103,5503 drain source reservoir 10104,5504 partition plate 10106,3306,5506 epitaxial growth chamber 1071,1072,2207,3307,4071,
4072, 5507, 6071, 6072 Epitaxial growth source

Claims (28)

[Claims] 1. A wafer storage space for holding a back surface of at least one set of semiconductor wafers in contact with an inner side wall and holding the surfaces so as to face each other at a predetermined interval, and inserts and discharges a source into and from the wafer storage space. Injection port, or a holder body provided with an injection port for injecting a source into the wafer storage space and a discharge port for discharging the source from the wafer storage space, and a holder cover that covers an opening surface of the holder body, A wafer holder comprising: 2. A predetermined gap is provided between an outer edge of the semiconductor wafer, a wall of the holder body where the outer edge of the semiconductor wafer is close to the inside of the wafer storage space, and an outer edge of the semiconductor wafer. 2. The wafer according to claim 1, wherein the amount of the source entering the outer edge portion of the semiconductor wafer is limited to a predetermined amount, and diffusion of the epitaxial growth material contained in the source to the edge portion of the semiconductor wafer near the outer edge portion is suppressed. holder. 3. The wafer holder according to claim 2, wherein a gap between a wall in the wafer storage space and an outer edge of the semiconductor wafer is 4.9 mm or less. 4. A wall in which the outer edge of the semiconductor wafer and the outer edge of the semiconductor wafer in the wafer accommodating space of the holder main body are close to each other, except for the portion where the inlet / outlet or the inlet / outlet exists. Between the entire periphery of the
4. The wafer holder according to claim 1, wherein the semiconductor wafer is held with a predetermined gap. 5. A taper portion or a step portion is provided on a wall of the holder main body in the wafer storage space close to an outer edge of the semiconductor wafer so that a diameter of the back surface side of the semiconductor wafer is larger than a diameter of the front surface side. The wafer holder according to any one of claims 1 to 4, wherein the wafer holder is provided. 6. The semiconductor device according to claim 5, wherein said tapered portion or step portion provided on a wall of said wafer storage space of said holder main body has a minimum diameter of at least 4 mm smaller than a diameter of a semiconductor wafer. The described wafer holder. 7. The taper portion or the step portion provided on the wall of the wafer storage space of the holder body has a minimum diameter that is equal to or greater than the diameter of a portion of the semiconductor wafer where chamfering is not performed. The wafer holder according to claim 5, wherein 8. A U-shaped or semi-circular pocket is formed in the semiconductor wafer accommodating space of the holder main body so as to conform to an outer peripheral shape of the semiconductor wafer. The holder cover, which is placed and held in a wafer storage space and covers an opening surface of the holder main body, has a semicircular surface so as to conform to an outer peripheral shape of the semiconductor wafer. 8. The wafer holder according to any one of 7. 9. A wafer holding plate having a disk shape, and a U-shaped or semi-circular groove provided so as to surround a peripheral region excluding an opening surface of the wafer holding plate, and at least one set of A holder plate in which each back surface of the semiconductor wafer is in contact with both surfaces of the wafer holding plate and each outer edge of the semiconductor wafer is inserted and held in the groove in a back-to-back state; a U-shape adapted to the outer periphery of the semiconductor wafer Or a holder cover that has a semicircular groove, covers the opening surface of the wafer holding plate, and holds the outer edge of the semiconductor wafer held by the wafer holding plate by being inserted into the groove and holding the same. The two sets are provided, and the holder plate and the holder cover are stacked, so that the respective surfaces of the two semiconductor wafers face each other at a predetermined interval with a predetermined interval therebetween. Wafer holder, characterized in that it is urchin retained. 10. A wafer holding plate and a U-shaped or semicircular groove provided so as to surround a peripheral region excluding an opening surface of the wafer holding plate. A holder plate in which the outer edge of the semiconductor wafer is fitted and held in the groove while being in contact with the inner bottom surface of the wafer holding plate; anda U-shaped or semicircular groove adapted to the outer periphery of the semiconductor wafer, A holder cover that covers an opening surface of the wafer holding plate and that holds an outer edge of the semiconductor wafer held by the wafer holding plate by being inserted into a groove, and a holder cover. On the upper surface of the held set of the holder plate and the holder cover, the other holder plate is placed so that another semiconductor wafer is sandwiched therebetween, and the two semiconductor wafers are held together. Wafer holder, wherein a surface of, respectively is held so as to face at a predetermined distance. 11. An inlet for injecting a source and an outlet for discharging a source are provided in the groove of the wafer holding plate, and the inlet and the outlet are held by the wafer holding plate. 11. The wafer holder according to claim 9, wherein a step having a thickness of at least about half of the semiconductor wafer is formed. 12. The predetermined distance between two semiconductor wafers held by at least two sets of the wafer holding plate and the holder cover so that the surfaces thereof face each other is about 0.
The wafer holder according to any one of claims 9 to 11, wherein the thickness is 3 mm to 5.0 mm. 13. A source reservoir for accommodating a source used for liquid phase epitaxial growth, an epitaxial growth chamber positioned below the source reservoir for accommodating a semiconductor wafer, and provided between the source reservoir and the epitaxial growth chamber. A source passage, and a pre-chamber provided in a part of the source passage, wherein when the source stored in the source reservoir is introduced into the epitaxial growth chamber through the source passage, An epitaxial growth apparatus characterized in that a source is stirred in a chamber. 14. A drain source reservoir provided between the source passage and the source passage via a source cut-off portion. When the source cut-off portion is opened, a source remaining in the source passage and / or the front chamber is removed. 14. The epitaxial growth apparatus according to claim 13, wherein the liquid is discharged to the discharge source reservoir. 15. A source reservoir for separately storing at least two types of sources used for liquid phase epitaxial growth, an epitaxial growth chamber located below the source reservoir for storing a semiconductor wafer, the source reservoir and the epitaxial growth chamber. And a source passage provided separately for each source between the source and the source. 16. The apparatus according to claim 16, further comprising a drain source reservoir provided between the source passage and the source passage via a source cut-off portion. When the source cut-off portion is opened, the source remaining in the source passage is discharged to the drain source reservoir. The epitaxial growth apparatus according to claim 15, wherein the epitaxial growth is performed. 17. An exhaust source reservoir provided separately for each source via a source cutoff portion between the source passage and the source passage, wherein when the source cutoff portion is opened, the source remaining in the source passage is removed. 16. The epitaxial growth apparatus according to claim 15, wherein the source is separately discharged into a drain source reservoir for each source. 18. A source reservoir for accommodating a source used for liquid phase epitaxial growth, and a wafer holder for holding a semiconductor wafer, wherein the back surface of at least one set of the semiconductor wafer is brought into contact with the inner side wall and the surface is spaced at a predetermined interval. It has a wafer storage space for holding it oppositely, and has a spout port for injecting and discharging a source into and out of the wafer storage space, or an injection port for injecting a source into the wafer storage space and discharging the source from inside the wafer storage section. A wafer holder having a holder main body provided with a discharge port to be provided, and a holder cover covering an opening surface of the holder main body; and epitaxial growth for storing a semiconductor wafer held below the source holder and held by the wafer holder. A source passage provided between the source reservoir and the epitaxial growth chamber; And a front chamber provided in a part of the source passage, wherein when the source housed in the source reservoir is introduced into the epitaxial growth chamber through the source passage, the source is placed in the front chamber. An epitaxial growth apparatus characterized by being stirred. 19. A high-temperature soaking region heated by a heating means to form a substantially uniform temperature distribution, and a low-temperature region located above the high-temperature soaking region and lower in temperature than the high-temperature soaking region. A heating furnace having: a gas supply means for supplying a reducing gas and / or an inert gas to the heating furnace; and a metal solute provided in the high-temperature soaking region in the heating furnace and containing a semiconductor material used for epitaxial growth. A source reservoir for storing a source dissolved in a solvent containing, a wafer holder for holding a plurality of semiconductor wafers, and moving the wafer holder in the heating furnace in a vertical direction, and holding the wafer holder for epitaxial growth. A wafer holder moving means for immersing the separated semiconductor wafer in a source in the source reservoir; and a stirring blade for stirring the source in the source reservoir. And,
And a stirring blade moving means for moving the stirring blade in the vertical direction to move the stirring blade into and out of the source. 20. A semiconductor member containing an element constituting the solute, a semiconductor member holding structure for holding the semiconductor member, and the semiconductor member holding structure being moved in a vertical direction so as to move the source in the source reservoir. 20. The semiconductor liquid phase epitaxial growth apparatus according to claim 19, further comprising: a semiconductor member moving unit that moves the semiconductor member in and out. 21. The semiconductor liquid phase epitaxial growth apparatus according to claim 19, wherein at least a part of said stirring blade is formed of a semiconductor material containing an element constituting said solute. 22. A high-temperature soaking region heated by the heating means to form a substantially uniform temperature distribution, and a low-temperature region located above the high-temperature soaking region and lower in temperature than the high-temperature soaking region. A heating furnace having: a gas supply means for supplying a reducing gas and / or an inert gas to the heating furnace; and a metal solute provided in the high-temperature soaking region in the heating furnace and containing a semiconductor material used for epitaxial growth. A source reservoir for storing a source dissolved in a solvent containing: a wafer holder for holding a semiconductor wafer, wherein the back surface of at least one set of semiconductor wafers is brought into contact with an inner side wall so that the surfaces face each other at a predetermined interval. Having a wafer storage space for holding, an injection port for injecting and discharging a source into and out of the wafer storage space, or an injection port for injecting a source into the wafer storage space and A holder body provided with a discharge port for discharging a source from the wafer storage section, a wafer holder having a holder cover covering an opening surface of the holder body, and moving the wafer holder in the heating furnace in a vertical direction, When performing epitaxial growth, a wafer holder moving means for immersing a semiconductor wafer held by the wafer holder in a source in the source reservoir, and a stirring blade for stirring the source in the source reservoir,
And a stirring blade moving means for moving the stirring blade in the vertical direction to move the stirring blade into and out of the source. 23. A step of holding a plurality of semiconductor wafers in a wafer holder; a step of housing the semiconductor wafer held in the wafer holder in an epitaxial growth chamber; and a step of supplying a reducing gas and / or an inert gas to the epitaxial growth chamber. Inflowing; heating the epitaxial growth chamber to a predetermined temperature; flowing a source contained in a source reservoir into a front chamber and stirring the source; and introducing a source into the epitaxial growth chamber to form a semiconductor wafer. Contacting the source with, and decreasing the temperature in the epitaxial growth chamber,
A semiconductor liquid phase epitaxial growth method, comprising: performing a epitaxial growth on a semiconductor wafer; and discharging the source in the epitaxial growth chamber to terminate the epitaxial growth. 24. A step of holding a plurality of semiconductor wafers in a wafer holder; a step of housing the semiconductor wafer held in the wafer holder in an epitaxial growth chamber; and a step of supplying a reducing gas and / or an inert gas to the epitaxial growth chamber. Flowing into the epitaxial growth chamber; and heating the epitaxial growth chamber to a predetermined temperature, and introducing a first source into the epitaxial growth chamber among at least two types of sources separately stored in the source reservoir for each source. Contacting the semiconductor wafer with the first source, and lowering the temperature in the epitaxial growth chamber,
A step of performing epitaxial growth on a semiconductor wafer; a step of discharging the first source in the epitaxial growth chamber to terminate the epitaxial growth; and introducing a second source of the at least two types of sources into the epitaxial growth chamber. Contacting the second source with a semiconductor wafer; and decreasing the temperature in the epitaxial growth chamber;
A semiconductor liquid phase epitaxial growth method, comprising: performing a epitaxial growth on a semiconductor wafer; and discharging the second source in the epitaxial growth chamber to terminate the epitaxial growth. 25. A wafer holding space for holding a plurality of semiconductor wafers in a wafer holder, wherein a back surface of at least one set of semiconductor wafers is brought into contact with an inner side wall and held so that the surfaces face each other at a predetermined interval. A holder body provided with a discharge port for pouring and discharging a source into and out of the wafer storage space, or an injection port for injecting a source into the wafer storage space and a discharge port for discharging a source from the wafer storage space. Using a wafer holder having a holder cover that covers the opening surface of the holder body,
A step of holding a semiconductor wafer, a step of housing the semiconductor wafer held by the wafer holder in an epitaxial growth chamber, a step of flowing a reducing gas and / or an inert gas into the epitaxial growth chamber, Heating to a temperature, flowing the source housed in the source reservoir into the front chamber and stirring, and then introducing the source into the epitaxial growth chamber and bringing the source into contact with the semiconductor wafer; As the indoor temperature drops,
A semiconductor liquid phase epitaxial growth method, comprising: performing a epitaxial growth on a semiconductor wafer; and discharging the source in the epitaxial growth chamber to terminate the epitaxial growth. 26. A step of holding a plurality of semiconductor wafers on a wafer holder; a high-temperature soaking region heated by a heating means to form a substantially uniform temperature distribution; Holding the wafer holder holding the semiconductor wafer in the low-temperature area in the heating furnace having a low-temperature area lower than the high-temperature soaking area; and reducing gas and / or inert gas in the heating furnace. A step of flowing gas; a step of heating by the heating means such that the high-temperature soaking region in the heating furnace has a predetermined temperature; and lowering the wafer holder from the low-temperature region to the position of the high-temperature soaking region. Raising the temperature of the wafer holder and the semiconductor wafer to the predetermined temperature; and moving the wafer holder and the semiconductor wafer downward to form the epitaxial wafer. A step of putting a solute containing a semiconductor material used in a solvent containing a metal dissolved in a solvent containing the source into the source in a source reservoir, and lowering the temperature of the high-temperature soaking region to perform epitaxial growth on a semiconductor wafer. And e. Terminating the epitaxial growth by pulling out the wafer holder from the source. 27. A step of holding a plurality of semiconductor wafers on a wafer holder; a high-temperature soaking region heated by a heating means to form a substantially uniform temperature distribution; Holding the wafer holder holding the semiconductor wafer in the low-temperature area in the heating furnace having a low-temperature area lower than the high-temperature soaking area; and reducing gas and / or inert gas in the heating furnace. A step of flowing gas; a step of heating by the heating means such that the high-temperature soaking region in the heating furnace has a predetermined temperature; and lowering the wafer holder from the low-temperature region to the position of the high-temperature soaking region. Raising the temperature of the wafer holder and the semiconductor wafer to the predetermined temperature, and placing different first and second sources in the high-temperature soaking area of the heating furnace, respectively. First and second source reservoirs are provided, a step of moving the wafer holder and the semiconductor wafer downward into the first source, and lowering the temperature of the high-temperature soaking region. Forming a first epitaxial layer by performing a first epitaxial growth on a semiconductor wafer, extracting the wafer holder from the first source, and completing the first epitaxial growth; Moving the wafer holder and the semiconductor wafer downward, and lowering the temperature of the high-temperature soaking region, and performing a second epitaxial growth on the surface of the first epitaxial layer to form a second epitaxial layer. A second epitaxial growth by pulling out the wafer holder from the second source Semiconductor liquid phase epitaxial growth method characterized by comprising the steps of ending, the. 28. A step of holding a plurality of semiconductor wafers on a wafer holder, wherein a wafer storage space holds at least one set of semiconductor wafers such that the inner back surface thereof is in contact with a side wall and the surfaces face each other at a predetermined interval. A holder body having a spout for pouring a source into and out of the wafer storage space, or an inlet for injecting a source into the wafer storage space and an outlet for discharging the source from the wafer storage space. A step of holding a semiconductor wafer using a wafer holder having a holder cover that covers an opening surface of the holder body; and a high-temperature soaking region that is heated by a heating unit to form a substantially uniform temperature distribution. And a low-temperature region located above the high-temperature soaking region and having a lower temperature than the high-temperature soaking region. A step of holding the wafer holder holding the conductor wafer; a step of flowing a reducing gas and / or an inert gas into the heating furnace; and a step of setting a high-temperature soaking area in the heating furnace to a predetermined temperature. A step of heating by a heating means; a step of lowering the wafer holder from the low-temperature area to the position of the high-temperature soaking area to raise the temperature of the wafer holder and the semiconductor wafer to the predetermined temperature; Is moved downward, a step of putting the solute containing a semiconductor material used for epitaxial growth in a solvent containing a metal in a solvent containing a metal into the source in the source reservoir, and lowering the temperature of the high-temperature soaking region. Performing epitaxial growth on a semiconductor wafer; and withdrawing the wafer holder from the source, Semiconductor liquid phase epitaxial growth method characterized by comprising the steps of: terminating the catcher Le growth,.