JP2001237193A - Wafer boat for heat-treating device and heat-treating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable low-cost and easy manufacture of a wafer boat even in the case where the diameter of semiconductor wafers to be housed in the wafer boat, which is used when the wafers are inserted in a heat-treating device, is long. SOLUTION: A carrier part 22 capable of housing a plurality of semiconductor wafers at prescribed intervals is provided. Supports 24 to support the carrier 22 are provided. The carrier 22 and the supports 24 are provided in such a way as to be able to split from each other. The supports 24 have a size to occupy a space wider than that of the carrier 22 within a reaction tube of a heat-treating device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer boat for a heat treatment apparatus and a heat treatment method, and more particularly to a wafer boat used when a plurality of semiconductor wafers are inserted into a heat treatment apparatus and using the wafer boat. It relates to a heat treatment method.

[0002]

2. Description of the Related Art MOS (Metal Oxide Semiconductor)
Semiconductor devices such as LSIs (Large Scale Integration circuits) and bipolar LSIs require an oxidation process or CVD (Ch
It is manufactured through many heat treatment steps such as an emical vapor deposition (deposition) step or a diffusion step. In these heat treatment steps, a vertical heat treatment apparatus and a wafer boat for a vertical heat treatment apparatus (hereinafter simply referred to as “wafer boat”) may be used.

FIG. 6 is a conceptual diagram showing a reaction tube 10 of a general vertical heat treatment apparatus and a conventional wafer boat 12. The wafer boat 12 is inserted into the reaction tube 10 with the plurality of semiconductor wafers 14 and the plurality of dummy wafers 16 mounted thereon and mounted on the heat retaining tower 17. The reaction tube 10 has a soaking zone 18 in which stable heat treatment can be performed. The semiconductor wafer 14 is mounted on the wafer boat 12 so as to fit in the soaking zone 18. Then, the dummy wafer 16 is mounted on a portion deviating from the soaking zone 18.

[0004]

In recent years, the diameter of a semiconductor wafer has been increased with the progress of semiconductor manufacturing technology, and the diameter of the conventional semiconductor wafer has shifted from 200 mm to 300 mm.
In addition, a semiconductor wafer having a diameter of 400 mm may be used, including those at a research stage. The thickness of the semiconductor wafer increases as the diameter increases. Therefore, the width of the groove to be formed in the wafer boat and the total height for accommodating a predetermined number of wafers also need to be changed in accordance with the change in the diameter of the semiconductor wafer.

For example, a wafer boat for mounting a 300 mm semiconductor wafer has a groove width (for example, about 8 to 18 mm) that can accommodate the wafer at an appropriate interval.
And a total height (for example, about 785 mm to 945 mm) reaching the soaking zone of the heat treatment apparatus is required. When newly forming such a wafer boat, it is necessary to confirm a number of items such as the shape of the wafer boat and the finishing accuracy of the groove by experiments.

[0006] By the way, existing equipment for manufacturing or inspecting a 200 mm wafer boat may not be compatible with a wafer boat for accommodating larger diameter wafers. Therefore, a new investment is required to manufacture a wafer boat for 300 mm or 400 mm.
Further, the manufacture of such a wafer boat requires more materials (quartz and silicon carbide (SiC)) than in the case of manufacturing a wafer boat corresponding to 200 mm. For these reasons, the prototyping of a wafer boat for storing large diameter semiconductor wafers requires a longer prototyping time and a three-
Up to five times the cost is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is a wafer boat for a heat treatment apparatus suitable for an experiment for efficiently developing a wafer boat corresponding to a new size semiconductor wafer. The first object is to provide The present invention also provides a heat treatment method performed using a wafer boat as described above.
The purpose of.

[0008]

In order to achieve the first object, an invention according to claim 1 is a wafer boat used in a semiconductor wafer heat treatment apparatus, wherein a plurality of semiconductor wafers are stored at predetermined intervals. And a support portion for supporting the carrier portion, the carrier portion and the support portion can be divided, and inside the reaction tube of the heat treatment apparatus, the support portion is Occupying a larger space than the carrier portion.

According to a second aspect of the present invention, there is provided a wafer boat used in a semiconductor wafer heat treatment apparatus, the carrier having a plurality of storage grooves for storing a plurality of semiconductor wafers at predetermined intervals, and supporting the carrier. Comprising a supporting portion, the carrier portion and the supporting portion are divisible,
The carrier unit includes a plurality of types of storage grooves having different structures.

According to a third aspect of the present invention, there is provided the wafer boat for a heat treatment apparatus according to the second aspect, wherein the plurality of carrier portions are provided, and the plurality of carrier portions are separable from each other and overlap each other. It is characterized in that matching is possible.

The invention described in claim 4 is the invention according to claim 2 or 3.
2. The wafer boat for a heat treatment apparatus according to claim 1, wherein all of the storage grooves included in the single carrier unit have different structures.

According to a fifth aspect of the present invention, there is provided the wafer boat for a heat treatment apparatus according to the third aspect, wherein all the accommodating grooves included in the plurality of carrier portions have structures different from each other.

[0013] In order to achieve the second object, the present invention is directed to claim 6.
The described invention is a method for heat-treating a semiconductor wafer, wherein the step of storing the semiconductor wafer in a wafer boat, the step of carrying the wafer boat into a reaction tube, and the step of heating the semiconductor wafer in the reaction tube Wherein the wafer boat is the wafer boat for a heat treatment apparatus according to any one of claims 1 to 5.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals, and redundant description will be omitted.

Embodiment 1 FIG. 1 shows a wafer boat 20 according to the first embodiment of the present invention. The wafer boat 20
This member is used to insert a plurality of semiconductor wafers into a vertical heat treatment apparatus, and includes a carrier section 22 and a support section 24. The carrier section 22 includes a top plate 26 and a bottom plate 2.
8 and three wafer support columns 30. The wafer support column 30 is provided with a plurality of fins 32 for supporting a semiconductor wafer. The support part 24 includes the top plate 3
4, a bottom plate 36 and three columns 38. The carrier section 22 and the support section 24 are each made of quartz or silicon carbide SiC.

FIG. 2 is a view showing the carrier section 22 and the support section 24 separately. As shown in FIG. 2, the carrier part 22 and the support part 24 can be divided. On the upper surface of the top plate 34 of the support portion 24, three fitting protrusions 40 are provided. On the other hand, the bottom plate 28 of the carrier portion 22 has
A concave portion (not shown) that fits with the convex portion 40 is provided. The carrier part 22 is mounted on the support part 24 so that the above-mentioned convex part 40 fits into a concave part (not shown) of the bottom surface 28.

FIG. 3 shows a wafer boat 20 according to this embodiment.
Shows a state inserted into the reaction tube 10 of the vertical heat treatment apparatus. In FIG. 3, the wafer boat 20 is mounted on the heat retaining tower 17 with a plurality of semiconductor wafers 14 held in a carrier section 22. Carrier part 22
In this state, the plurality of semiconductor wafers 14 stored in the inside are accommodated in the soaking zone 18 of the reaction tube 10.
As shown in FIG. 3, the wafer boat 20 of the present embodiment
The support portion 24 is configured to occupy a larger space inside the reaction tube 10 than the carrier portion 22.

In the present embodiment, the carrier portion 22 of the wafer boat 20 is capable of accommodating a plurality of semiconductor wafers 14 having a diameter of 300 mm and has a total height of 10 mm.
It is provided to be 0 mm. If the total height is about 100 mm, the manufacture and inspection of the carrier part 20 are performed with a diameter
It can be easily performed using equipment for manufacturing or inspecting a wafer boat for semiconductor wafers of 00 mm, that is, existing equipment widely used. For this reason,
The carrier section 22 can be manufactured relatively inexpensively and easily.

The support portion 24 is a member provided only for allowing the carrier portion 22 to reach the soaking zone 18.
Does not require subtle precision. For this reason, the support part 24 can be manufactured cheaply and easily. As described above, both the carrier portion 22 and the support portion 24 constituting the wafer boat 20 of the present embodiment can be manufactured easily at low cost. Therefore, according to the structure of the present embodiment, a wafer boat 20 capable of holding the semiconductor wafer 14 having a diameter of 300 mm in the soaking zone 18 can be realized at low cost and easily.

Embodiment 2 Next, a wafer boat 50 according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 shows a state where the wafer boat 50 according to the second embodiment of the present invention is inserted into the reaction tube 10 of the vertical heat treatment apparatus. FIG. 5 is a view showing the carrier section 22 and the support section 24 separately.

In this embodiment, the wafer boat 50
Has three carrier parts 52 and one support part 54 that can be divided. The carrier section 52 has three protrusions 56 for fitting on the upper surface of the top plate 26 except for three points.
It has the same configuration as carrier portion 22 in the first embodiment. The support 54 has the same configuration as the support 24 in the first embodiment, except that the support 58 is short. In the present embodiment, the support portion 54 is provided such that all of the three carrier portions 52 fit in the soaking zone 18 of the vertical heat treatment apparatus.

As in the first embodiment, the bottom plate 28 of the carrier portion 52 has a concave portion (not shown) fitted with the convex portion 40 provided on the support portion 54 or the convex portion 56 provided on another carrier portion 52. Z) is provided. The carrier section 52
The projections 40 or 56 described above are mounted on the support portion 54 in a state of being overlapped with each other such that the projections 40 or 56 are fitted into recesses (not shown) of the bottom surface 28.

In the present embodiment, the carrier portion 52 of the wafer boat 50 is designed to accommodate a plurality of semiconductor wafers 14 having a diameter of 300 mm and has a total height of 10 mm.
It is provided to be 0 mm. In the wafer boat 50, the accuracy of the groove width for accommodating the semiconductor wafer 14 is important. In order to transport the semiconductor wafer 14 without any trouble, it is necessary to suppress the dimensional error of all the grooves to, for example, about 3/100.

The above-mentioned dimensional error is a value obtained by converting an error contained in each groove into an error of the entire wafer boat, and expressing the converted value assuming that the total height of the wafer boat is 100. More specifically, the error is obtained by multiplying the error of each groove by the number of grooves included in the wafer boat, dividing the multiplied value by the total height of the wafer boat, and further multiplying by 100.

In the wafer boat 50 of the present embodiment,
The accuracy of the groove with respect to the total height of the carrier portion 54 could be reduced to 1/100 or less because the total height was low (100 mm). Therefore, even if the three carrier portions 54 are overlapped, the dimensional error of the groove can be suppressed to within 3/100. Therefore, according to the wafer boat 50, the semiconductor wafer 14 can be transported without any inconvenience.

Further, the carrier portion 52 and the support portion 54 constituting the wafer boat 50 of the present embodiment can be manufactured inexpensively and easily as in the case of the first embodiment. Further, according to the wafer boat 50 of the present embodiment, since the carrier portions 52 are overlapped, the first embodiment
In this case, a larger number of semiconductor wafers 14 can be processed at one time. For this reason, the wafer boat 50 can be used even when mass production of semiconductor devices is desired.

Further, in the structure of this embodiment, when one of the carrier portions 52 is damaged or deformed, only the carrier portion 52 can be repaired or replaced. For this reason, the wafer boat 50 of the present embodiment can be used economically for a long period of time as compared with a wafer boat in which the whole is integrally provided.

By the way, in the first and second embodiments described above.
In the above, the diameter of the semiconductor wafer 14 stored in the wafer boat 20 or 50 is 300 mm, but the present invention is not limited to this, and the diameter may be 200 mm or 400 mm.

In Embodiments 1 and 2 described above, the connecting mechanism between the support portions 24 and 54 and the carrier portions 22 and 52 and the connecting mechanism between the carrier portions 52 are different from the convex portion 4.
Although they are realized by 0, 56 and a concave portion fitted to them, the configuration of the coupling mechanism is not limited to this.
That is, the connection mechanism may be any mechanism that can stably maintain the connection between the support portions 24 and 54 and the carrier portions 22 and 52.

Embodiment 3 Next, a wafer boat according to a third embodiment of the present invention will be described with reference to FIGS. 1 and 2 again. As described above, the carrier portion 22 provided in the wafer boat 20 according to the first embodiment
Are provided. Three fins 32 are provided to support one semiconductor wafer 14. Hereinafter, the supporting portion formed by the three fins 32 is referred to as a “storage groove” of the semiconductor wafer 14.

The wafer boat of the present embodiment has the same configuration as the wafer boat 20 of the first embodiment except that a plurality of storage grooves provided in the same carrier portion 22 have different structures. Have. Specifically, in the present embodiment, the fins 32 forming the individual storage grooves are provided.
Is the shape, surface condition, length, width, area,
And the angles are different. That is, in the present embodiment, the carrier portion 22 is formed such that all the accommodating grooves provided therein have different structures.

When a semiconductor wafer 14 having a diameter of 300 mm is held in a wafer boat, defects due to its own weight are more likely to occur on the wafer than when the diameter of the wafer is 200 mm.
Further, in the case of the 300 mm semiconductor wafer 14, a defect (slip) due to thermal stress or thermal deformation is more likely to occur in the vicinity of the portion supported by the fins 32 than the 200 mm wafer. For this reason, a wafer boat corresponding to the 300 mm semiconductor wafer 14 cannot be realized by simply increasing the storage groove for storing the 200 mm wafer.

Therefore, in the process of developing a wafer boat corresponding to the semiconductor wafer 14 of 300 mm, it is necessary to experimentally find the optimum storage groove structure by changing the shape and surface condition of the fin 32. In this case, there are many items to be considered for optimization, such as the angle, thickness, interval, width, surface finish, and depth of the storage groove of the fin 32, and each of those items is changed to, for example, three levels. If an experiment is to be performed, it is necessary to perform an experiment on a considerable number of storage grooves.

As described above, the wafer boat of this embodiment is provided with a plurality of storage grooves having different structures in one carrier section 22. Therefore, according to the wafer boat, experimental data on a plurality of storage grooves having different structures can be collected by one heat treatment. For this reason,
According to the use of the wafer boat of the present embodiment, the development of a wafer boat accommodating a semiconductor wafer 14 of a new size is efficiently advanced, and the development period is significantly shortened.
The development cost can be significantly reduced.

Embodiment 4 FIG. Next, a wafer boat according to a fourth embodiment of the present invention will be described with reference to FIGS. 4 and 5 again. As described above, the wafer boat 20 according to the second embodiment includes the three carrier units 52. Each of the carrier portions 52 includes a plurality of storage grooves (constituted by three fins 32) for holding the semiconductor wafer 14.

As in the case of the third embodiment, the wafer boat of the present embodiment is different from the third embodiment in that a plurality of storage grooves provided in the same carrier portion 52 have different structures, and three wafer carriers 52 are provided. All the storage grooves have the same structure as the wafer boat 50 of the above-described second embodiment except that the storage grooves do not overlap. That is, in the present embodiment, the fins 32 constituting the individual storage grooves are provided in the form, surface condition, length, and width of each storage groove so that the structures of all the storage grooves included in the wafer boat do not overlap. , Area, angle, and the like.

According to the wafer boat of the present embodiment, since three carrier portions 52 are provided so as to overlap with each other, compared with the wafer boat of the third embodiment, a large number of storage grooves can be formed in one experiment. Experimental data can be obtained. For this reason, according to the wafer boat of the present embodiment, the development of a wafer boat for accommodating a semiconductor wafer 14 of a new size can be advanced more efficiently than the wafer boat of the third embodiment. .

In the above-described third embodiment, all the storage grooves included in the single carrier portion 22 have different structures. In the above-described fourth embodiment, all the storage grooves included in the wafer boat, that is, all the storage grooves included in the three carrier portions 52 have different structures. However, the present invention is not limited to this, and it is sufficient that a plurality of storage grooves having different structures are prepared in a single wafer boat, and all the storage grooves have different structures from each other. You don't have to. In the case where the same storage groove having the same structure is provided in a single wafer boat, a single heat treatment can secure the number of repetitions of the experiment with respect to the storage groove. Can be enhanced.

In Embodiments 3 and 4 described above, the storage grooves included in the carrier portions 22 and 52 are each formed by three fins 32. However, the number of the fins 32 forming the storage grooves is However, the present invention is not limited to this.
Further, the number of the fins 32 constituting the storage grooves does not need to be uniform in the same carrier portions 22 and 52, and the storage grooves having different numbers of the fins 32 are provided in the same carrier portions 22 and 52. May coexist.

[0040]

Since the present invention is configured as described above, it has the following effects. Claim 1
According to the described invention, since the carrier portion and the support portion are divided, each can be manufactured at low cost and easily. In addition, since the carrier portion is sufficiently small, the cost can be suppressed, and the carrier portion can be reliably located in the soaking layer of the reaction tube. Therefore, according to the present invention, even when the semiconductor wafer to be stored has a large diameter, a wafer boat can be realized at low cost and easily.

According to the second aspect of the present invention, a plurality of types of storage grooves can be prepared in the carrier portion that can be divided from the support portion. In this case, experimental data on a large number of storage grooves can be obtained by one heat treatment. Therefore, according to the present invention, the development of a wafer boat for storing a semiconductor wafer of a new size can be efficiently advanced.

According to the third aspect of the present invention, since a plurality of carrier portions are provided, it is possible to obtain a larger number of experimental data on the storage grooves by a single heat treatment than in the case where only one carrier portion is provided. it can. Therefore, according to the present invention, the development of a wafer boat for accommodating a semiconductor wafer of a new size can be efficiently advanced.

According to the fourth aspect of the present invention, since all the storage grooves prepared in a single carrier portion have different structures, experimental data of a large number of storage grooves can be efficiently obtained by one heat treatment. be able to.

According to the fifth aspect of the present invention, all of the storage grooves included in the plurality of carrier portions have different structures from each other. Experimental data can be obtained.

According to the sixth aspect of the present invention, by using the wafer boat according to any one of the first to fifth aspects, the heat treatment of the semiconductor wafer can be efficiently performed. Therefore, according to the present invention, the development cost of a semiconductor device can be significantly reduced, and the development can be promoted.

[Brief description of the drawings]

FIG. 1 is a front view of a wafer boat according to a first or third embodiment of the present invention.

FIG. 2 is a diagram showing a carrier section and a support section constituting the wafer boat shown in FIG. 1 separately.

FIG. 3 is a view showing a state in which the wafer boat shown in FIG. 1 is housed in a reaction tube of a vertical heat treatment apparatus.

FIG. 4 is a diagram showing a state where the wafer boat according to the second or fourth embodiment of the present invention is accommodated in a reaction tube of a vertical heat treatment apparatus.

FIG. 5 is a view showing a carrier part and a support part constituting the wafer boat shown in FIG. 4 in a divided manner.

FIG. 6 is a view showing a state in which a conventional wafer boat is housed in a reaction tube of a vertical heat treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reaction tube 14 Semiconductor wafer 18 Heat equalization zone 20; 50 Wafer boat 22; 52 Carrier part 24; 54 Support part 40; 56 Convex part

Claims (6)

[Claims] 1. A wafer boat used in a semiconductor wafer heat treatment apparatus, comprising: a carrier unit capable of accommodating a plurality of semiconductor wafers at predetermined intervals; and a support unit supporting the carrier unit. The support part is divideable, and inside the reaction tube of the heat treatment apparatus, the support part occupies a larger space than the carrier part. . 2. A wafer boat used in a semiconductor wafer heat treatment apparatus, comprising: a carrier section having a plurality of storage grooves for storing a plurality of semiconductor wafers at predetermined intervals; and a support section supporting the carrier section. The wafer boat for a heat treatment apparatus, wherein the carrier section and the support section are dividable, and the carrier section includes a plurality of types of storage grooves having different structures. 3. The wafer boat for a heat treatment apparatus according to claim 2, wherein a plurality of the carrier portions are provided, and the plurality of carrier portions are separable from each other and overlap with each other. . 4. The wafer boat for a heat treatment apparatus according to claim 2, wherein all the storage grooves included in the single carrier portion have different structures. 5. The wafer boat for a heat treatment apparatus according to claim 3, wherein all storage grooves included in the plurality of carrier parts have different structures from each other. 6. A method for heat-treating a semiconductor wafer, comprising: storing a semiconductor wafer in a wafer boat; loading the wafer boat into a reaction tube; and heating the semiconductor wafer in the reaction tube. 6. The heat treatment method according to claim 1, wherein the wafer boat is the wafer boat for a heat treatment apparatus according to any one of claims 1 to 5.