JPH02270329A - Short time heat treatment device - Google Patents

Abstract

PURPOSE:To obtain the title heat treatment device capable of heating a substrate to be heat-treated such as silicon wafer etc., evenly within a short time even in the atmosphere containing oxidizing gas such as atmospheric air, etc., by a method wherein a hollow shaped heater comprising SiC as a main material having multiple gas communicating holes on the bottom surface thereof is arranged opposite to the substrate on a retaining member. CONSTITUTION:The title heat treatment device provided with a retaining member 1 retaining a substrate to be heat-treated, a hollow shaped heater 3 comprising SiC as a main material having multiple gas communicating holes 4 on the bottom surface thereof arranged opposite to the substrate 9 on the retaining member 1 as well as an insulating gas leading-in pipe 5 inserted into the upper wall of the heater 3. For example, a shutter taking a shape having at least two shielding parts on both sides holding a non-shielding part 8 to be opened and closed by the said non-shielding part 8 and the shielding parts on both sides shifting in one direction is arranged between the retaining member 1 and the surface type heater 3. Furthermore, the retaining member 1 taking the shape to make the most part of the rear surface of the substrate 9 exposed with the member 1 retaining the substrate 9 is provided with another surface type heater 6 comrising SiC as a main material arranged on the rear surface side of the substrate 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a short-time heat treatment apparatus, and particularly to an apparatus for short-time heat treatment of semiconductor substrates such as silicon wafers.

(Prior Art) As a heat source for a short-time heat treatment apparatus, those using an infrared lamp have mainly been developed, and a carbon heater is known as a heat source using a planar heater.

However, when a silicon wafer is heated using the above-mentioned infrared rambra, the absorption coefficient of infrared rays differs from silicon single crystal, polycrystalline silicon, silicon oxide film,
G), and also varies depending on the impurity concentration in silicon and the phosphorus concentration in phosphide glass, and also depends on the refraction of light,
Reflection, interference, etc. occur, and it is extremely difficult to uniformly raise the temperature of a silicon wafer having an actual device structure.

On the other hand, with a planar heater, it is possible to heat the wafer using radiation and convection. However, if the heater is made of carbon and oxidizing gas remains in the atmosphere, it will burn, making it difficult to use it in practice unless it is in a high vacuum atmosphere. There was a problem that the advantages of convection could not be fully utilized.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned conventional problems, and it can uniformly heat-process substrates such as silicon wafers in a short time even in an atmosphere containing oxidizing gas such as the atmosphere. The present invention aims to provide a short-time heat treatment device that can raise the temperature.

[Structure of the Invention (Means for Solving the Problems) The present invention includes a support member that supports a substrate to be heat treated, and a support member disposed facing the substrate on the support member and having a plurality of gas flow holes in the bottom surface. This is a short-time heat treatment apparatus characterized by comprising a hollow heater mainly made of silicon carbide, and an insulating gas introduction pipe inserted into the upper wall of the heater.

(Function) According to the present invention, by forming the hollow heater mainly from silicon carbide which has excellent oxidation resistance, the substrate to be heat treated such as a silicon wafer can be heated even in an atmosphere containing oxidizing gas such as the atmosphere. The temperature can be raised in time. Alternatively, the heater may have a hollow shape, and a predetermined gas may be introduced into the hollow portion through an insulating gas introduction tube inserted into the heater, and be forcibly blown onto the opposing non-heat-treated substrate from the gas flow hole at the bottom of the heater. As a result, the temperature of the entire substrate including its periphery can be raised uniformly. Therefore, it is possible to uniformly raise the temperature of a substrate to be heat-treated such as a silicon wafer in a short time even in an atmosphere containing an oxidizing gas such as the atmosphere, thereby achieving short-time heating.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 and 2.

1 in the figure is a support member for supporting the substrate to be processed. This support member l is composed of four support rods 2,
The upper end of each support rod 2 is arranged so as to be located at a corner of a square drawn on a horizontal plane, and has a shape that is bent outward twice in the middle.

Above the support member I, a hollow cylindrical heater 3 made of high-purity silicon carbide and having a diameter of 200 mm and sealed upper and lower ends is arranged. A plurality of gas flow holes 4 are opened in the circular bottom of the hollow heater 3. An insulating gas introduction pipe 5 for introducing a desired gas into the heater 3 is inserted into the upper wall of the hollow heater 3. Further, a disk-shaped heater 6 made of high-purity silicon carbide and having a diameter of 200 ffl11 is arranged in the bent portion of the support rod 2 so as to face the bottom of the hollow heater 3 in parallel. Note that the bottom of the hollow heater 3 and the disk-shaped heater 6 are opposed to each other with an interval of 50 cm. A shutter 7 is disposed between the support member 1 and the bottom of the hollow heater 3. This shutter 7 has a shape that has a shielding part on at least both sides sandwiching the shielded part, and specifically, as shown in FIG.
It has a rectangular shape of 0 mv x 200 cm, with a hole 8 of 150 cm in diameter as a non-shielding part opened in the center. The support member I, the hollow heater 3, the disk-shaped heater 6, and the shutter 7 are housed in a chamber (not shown).

Next, the action of the short-time heat treatment apparatus described above is shown in Fig. 1(a).
This will be explained with reference to (C).

First, with the shutter 7 closed as shown in FIG. 3A, the temperature of the hollow heater 3 and the disc-shaped heater 6 is increased, and for example, argon gas is supplied to the hollow heater 3 from the gas introduction pipe 5. The substrate 9 to be heat treated is inserted into the four support rods 2 of the support member 1 using a holder (not shown).
Load on top.

When the temperature of both the hollow heater 3 and the disc-shaped heater 6 has risen sufficiently, the shutter 7 is moved in one direction (for example, to the left as shown by the arrow), and the hole in the shutter 7 is opened as shown in FIG. 8 is stopped at a location facing the substrate 9. As a result, the shutter 7 opens, and the top side of the substrate 9 is heated by the radiation and convection of the hollow heater 3 and the heated argon gas blown out from the plurality of circulation holes 4 at the bottom, and the back side of the substrate 9 is heated. The temperature is raised by a disc-shaped heater 6 and heat treatment is performed. The heat treatment temperature and time vary depending on the target of heat treatment (e.g., melting of phosphide glass film, activation of ion-implanted impurities, densification of silicon oxide film formed by vapor phase epitaxy, etc.), but are approximately 1100 to 1
The conditions are set at 200° C. for 5 to 20 seconds.

When the required heat treatment is completed, the shutter 7 is further moved in the same direction (to the left as shown by the arrow), and the shutter 7 is closed as shown in FIG. The shutter is unloaded from above the four support rods 2 in a direction perpendicular to the moving direction of the shutter 7.

According to the present invention, by forming the heater 3 on the hollow gauge from silicon carbide which has excellent oxidation resistance, heat treatment can be performed in an atmosphere containing an oxidizing gas. As a result, radiation and convection from the bottom of the hollow heater 3 are fully utilized, and the temperature increase rate can be increased, so that the substrate 9 to be heat-treated can be heated in a short time. Moreover, the gas introduction pipe 5 is inserted into the upper wall of the hollow heater 3,
A desired gas such as argon gas is supplied from the introduction pipe 5 to a heater.
By introducing the gas heated by the heater into the hollow part of the heater 3 and forcibly spraying it onto the substrate 9 from a plurality of gas flow holes 4 opened at the bottom of the heater 3 when the shutter 7 is opened, the substrate 9 can be heated extremely well. Can be heated evenly. In other words, when a planar heater heats the substrate facing it by radiation or convection, there is no inflow of cooling gas such as air from the outside near the center of the heater, so the substrate is heated by the radiation and convection effects of the heater. is heated to a high temperature. On the other hand, since the periphery of the heater is constantly cooled by convection of air or the like, there is a possibility that a difference in heating temperature may occur between the periphery of the heater and the vicinity of the center of the heater. For this reason, in the present invention, the gas introduction pipe 5
A desired gas is introduced into the hollow part of the heater 3 from the heater 3, and the gas heated by the heater is forcibly blown onto the substrate 9 from a plurality of gas flow holes 4 opened at the bottom of the heater 3. Since the temperature difference between the vicinity of the center and the periphery can be eliminated, the entire area including the periphery of the substrate 9 can be uniformly heated. Therefore, radiation and convection from the bottom of the hollow heater 3, and gas flow holes 4 at the bottom of the heater 3
By forcibly blowing heated gas from
can be heated extremely uniformly in a short period of time.

Furthermore, if a disk-shaped heater 6 is arranged in the support member 1 and the substrate 9 to be heat-treated is preheated by the disk-shaped heater 6 before being heated by the hollow heater 3, the shutter 7 can be heated.
The time required for the hollow heater 3 to raise the temperature to a predetermined temperature after opening can be shortened, making it possible to carry out heat treatment in an even shorter time.

Furthermore, if the shutter 7 having the shape described above is opened and closed by moving in one direction (for example, to the left), the non-shielding portion 68
Since the heating time of the substrate 9 to be heat-treated is the same at each point, the uniformity of the heat treatment within the surface of the substrate 9 can be improved. This will be specifically explained with reference to FIGS. 1(a) to 1(c) mentioned above.

Here, the description will be made assuming that the left end of the shutter hole 8 is Ls, the right end is Rs, the left end of the substrate 9 is the left end, and the right end is R. First, during the opening operation of moving the shutter 7 to the left (in the direction of the arrow) from the state shown in FIG. 1(a) to the state shown in FIG. The substrate 6 is heated by a hollow heater 3 facing the same substrate 6.
Finally, the left end of the shutter 7 is heated by the same heater 3 facing the left end Ls of the hole 8 of the shutter 7. That is, in the opening operation process of the shutter 7 from FIG. 1(a) to FIG. 1(b), the heating time is the shortest at the left end of the substrate 9, and the heating time becomes longer toward the right end R side. On the other hand, Fig. 1(b)
When the shutter 7 is moved in the same direction (to the left) from the state shown in FIG. 1(c) to the state shown in FIG.
The left end of the board 9 is the last shutter. The right end R of the hole 8 of the board 7.
It is shielded opposite s. In other words, in the closing operation process by the shutter 7 from FIG. 1(b) to FIG. 1(C), the right end R of the substrate 9 that is shielded first has the shortest heating time, and the left end side that is shielded last. The heating time becomes longer as the temperature increases. Therefore, by opening and closing the shutter 8 having 68 as a non-shielding part by moving it in one direction (for example, to the left), the right end R of the substrate 9, which is heated for the longest time when opened, is heated for the shortest time when closed. The left end of the board 9, which is heated for the shortest time when opened, is heated for the longest time when closed, so in total, both the right end and the left end of the board 9 are heated for the same time, and the board Uniform heat treatment can be performed on 9 surfaces. In particular, in short-time heat treatment, when opening and closing the shutter, the delay in the heating start time and heating end time at the left edge and right edge R of the substrate 9 greatly affects uneven heating. By moving in one direction to open and close, uneven heating due to the positional relationship between the hole 8 of the shutter 7 and the left and right ends of the substrate 9 can be eliminated, and the entire surface of the substrate 9 can be uniformly heat-treated for a short time.

Furthermore, if the loading and unloading of the substrate 9 by the holder is perpendicular to the moving direction of the shutter 7, even more uniform heating within the surface of the substrate 9 can be achieved.

In addition, in the above embodiment, the support member l, the heater 3
．． The substrate is loaded with the inside of the chamber (not shown) in which each member such as 6 is housed under reduced pressure, and then gas is introduced between several torr to several 100 torr to heat the substrate for a short period of time. It is also possible to depressurize and unload again. In such operations, when using a substrate with a treated surface that is easily oxidized or nitrided, if an inert gas is used as the gas introduced into the chamber, the heat treatment can be performed for a short time without oxidizing or nitriding the treated surface. I can do it. On the other hand, if a reactive gas, reactive plasma, or the like is used as the gas introduced into the chamber, the processing surface of the substrate can be oxidized or nitrided.

In the above embodiments, the hollow heaters and plate-shaped heaters were formed from high-purity silicon carbide, but they may also have a structure in which the surface of a base material of a high-melting point metal such as molybdenum or tantalum is coated with a high-purity silicon carbide film.

[Effects and Effects of the Invention] As detailed above, according to the present invention, the main material is silicon carbide, and the hollow shape has a plurality of gas flow holes opened at the bottom and a gas introduction pipe inserted into the upper wall. By using a heater, the temperature of a heat-treated substrate such as a silicon wafer can be raised uniformly in a short time even in an atmosphere containing oxidizing gas such as the air, and the substrate can also be oxidized or nitrided in an atmosphere of oxygen or nitrogen. It is possible to provide a short-time heat treatment apparatus that can perform heat treatment in a short time.

[Brief explanation of drawings]

FIGS. 1(a) to 1(C) show an embodiment of the present invention. l...Supporting member, 3...Hollow shaped heater, 4...
- Gas distribution hole, 5... Gas introduction pipe, 6... Disc-shaped heater, 7... Shutter, 8... Hole, 9... Heat-treated substrate. 20th

Claims (3)

[Claims] (1) A support member that supports a substrate to be heat-treated; a hollow heater made of silicon carbide, which is disposed on the support member to face the substrate and has a plurality of gas flow holes in its bottom; 1. A short-time heat treatment device characterized by comprising an insulating gas introduction pipe inserted into the upper wall of a heater. (2) A shutter that has a shielding part on at least both sides with a non-shielding part in between, and that opens and closes at the non-shielding part and the shielding parts on both sides by moving in one direction, is placed between the support member and the sheet heater. A short-time heat treatment apparatus according to claim 1, characterized in that: (3) The support member has a shape that exposes most of the back surface of the substrate to be heat-treated while supporting the substrate, and has another surface shape mainly made of silicon carbide on the back surface side of the substrate. 2. The short-time heat treatment apparatus according to claim 1, further comprising a heater.