JPH09213645A - Wafer supporting device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wafer-support device of a structure, wherein a slip or the like is not generated in a semiconductor wafer in bearing the wafer without producing flaws in the semiconductor wafer at a high-temperature treatment, and the device has a long use-life, by a method wherein the junction parts between support members, which are formed by an assembly of the support members, are coated with a CVD film. SOLUTION: This wafer support device is assembled using support members, which are made using silicon as the material for the support members, and after these support members are assembled, the whole of the support members is housed in a CVD furnace to form a polysilicon CVD film on each support member. Each support member consists of one pair of support body members 1, one pair of side frame members 3 and a support piece 51. In such a way, the device is manufactured into a constitution formed into such a structure that the whole of each support member is coated with a thin CVD film 100 by forming the CVD film on each support member of the support members mounted to each other and with a thick CVD film 101 formed on corner parts, which are formed between the support members, a risen CVD film 102 is formed on the parts of gaps 10 existing between the support members.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer supporting apparatus used as a boat for heat treatment of semiconductor wafers, and more particularly to a wafer supporting apparatus formed by assembling a plurality of supporting members.

[0002]

2. Description of the Related Art Quartz containing a small amount of heavy metal impurities is generally used as a wafer supporting device used for heat treatment of semiconductor wafers. However, since quartz is deformed at a high temperature (1100 ° C. or higher), there is a risk of causing a slip or the like on the supporting semiconductor wafer. Therefore, a silicon carbide (hereinafter referred to as SiC) boat or a silicon boat is actually used as a wafer supporting device for high temperature heat treatment. Since this SiC boat has a larger content of heavy metal impurities than a silicon boat, a silicon boat tends to be used when it is necessary to reduce heavy metal contamination.

Conventionally, a silicon boat as this type of wafer supporting device is formed by assembling a supporting member which is a component made of silicon, and this is shown in FIGS. 5 to 7. FIG. 5 is an explanatory view of an assembling state of a horizontal assembling type wafer supporting device, and FIG. 6 is an enlarged view of an assembling structure part when the wafer supporting device shown in FIG. 5 is assembled and its A′-
FIG. 7 is a cross-sectional view taken along the line A ', and FIG.

In FIG. 5, the horizontal assembling type wafer supporting apparatus comprises a pair of supporting body members 1 and 2 for supporting a semiconductor wafer, and a pair of side frame members for fixing both sides of the pair of supporting body members 1 and 2. 3, 4 and this support body member 1,
2 and the side frame members 3 and 4 are configured to include holding pieces 51 to 54 that hold the respective assembled portions of the side frame members 3 and 4. The support body member 1 (or 2) is composed of a substantially rectangular frame body, and the outer peripheral edge of the semiconductor wafer is sandwiched over almost the entire surface on one side of the frame body to cut the bearing groove 11 (or 21). The hook-shaped groove portions 12a and 13a (or 2) are formed on both sides of the frame body.
2a, 23a) having fitting protrusions 12, 13 (or 2)
2, 23) is formed. The side frame member 3
(Or 4) is composed of a plate having a substantially trapezoidal shape, and the rectangular mounting holes 31 and 3 are provided at the inverted C-shaped symmetrical positions on the plate.
2 (or 41, 42) are drilled, and these mounting holes 31, 3
The fitting protrusions 12, 13 (or 22, 23) are inserted into 2 (or 41, 42). The holding piece 5
Numerals 1 to 54 are concave groove portions that fit into the hook-shaped groove portions 12a and 13a (or 22a and 23a) of the fitting protrusion portions 12 and 13 (or 22 and 23) in the support body member 1 (or 2). It is a structure formed with.

In the vertical assembly type wafer supporting apparatus shown in FIG. 7, a pair of supporting body members 6 and 7 for supporting a semiconductor wafer and a substrate 8 for fixing the lower ends of the pair of supporting body members 6 and 7 are used. And the pair of support body members 6 and 7
And a top plate 9 for fixing the upper end of the. This support body member 6 (or 7) is provided with two support rods 61, 62 (or 71, 72) made of a rod-shaped body facing each other, and these two support rods 61, 62 (or 71, 72) are arranged. Is integrally assembled with the three fixing pieces 63 (or 73). The support rod 61 (or 62, 71, 72) is a bearing groove 61 for holding and supporting the outer peripheral edge portion of the semiconductor wafer.
c (or 62c, 71c, 72c) is formed over substantially the entire intermediate portion of one side surface, and the fixing holes 81 (or 82, 91, 82, 91, 82) of the base plate 8 and the top plate 9 are formed at both end portions of the rod-shaped body.
92) fixed protrusions 61a, 61b (or 6
2a, 62b, 71a, 71b, 72a, 72b) are formed in a protruding manner.

Next, the forming / assembling operation of each conventional wafer supporting apparatus based on the above construction will be described with reference to FIG. First, in the horizontal assembly type wafer supporting device, a pair of supporting main body members 1 and 2 and a pair of side frame members 3, 4 and 4
The individual holding pieces 51 to 54 are cut out from a polycrystalline or single crystal silicon ingot into a roughly predetermined shape (step 1).
1). In the vertical assembly type wafer support device, the pair of support body members 6, 7, the substrate 8 and the top plate 9 are cut out from a polycrystalline or single crystal silicon ingot into a roughly predetermined shape (step 11). Grinding is performed on each of the cut-out members with a predetermined designing accuracy (step 1).
2). A chemical etching process is performed using a mixed acid of HF and HNO3 in order to remove the processing strain layer and the stain remaining on the crystal of each member subjected to the grinding process (step 13).

The respective members that have been chemically etched are assembled (step 14). In this assembling work, the horizontal assembling type wafer supporting device is shown in FIGS. 6 (A) and 6 (B).
As shown as a part of assembly details, the fitting protrusions 12 and 22 of the pair of support body members 1 and 2 are inserted into the mounting holes 31 and 32 of the side frame member 3, and the inserted fitting protrusions 12 and
The holding pieces 51, 52 are fitted and locked into the hook-shaped groove portions 12 a, 22 a of the 22. Further, the fitting protrusions 13 and 23 of the pair of support body members 1 and 2 are inserted into the mounting holes 41 and 42 of the side frame member 4, and the hook-shaped groove 13 of the inserted fitting protrusions 13 and 23 is inserted.
The assembling is completed by fitting and locking the holding pieces 53 and 54 of a and 23a.

Further, in the assembling work, the vertical assembling type wafer supporting apparatus integrally assembles the two supporting rods 61, 62 (and 71, 72) with the three fixing pieces 63 (and 73). As a result, the pair of support body members 6 (and 7) are formed. Fixed projecting pieces 61a respectively projecting to the lower ends of the formed pair of support body members 6 (and 7),
62a (and 71a, 72a) are fixed holes 81 of the substrate 8.
(And 82) are fitted and fixed. Further, fixing projections 61b, 62b (and 71b, 72b) projecting toward the upper ends of the pair of support body members 6 (and 7) are provided on the top plate 9.
The assembly is completed by fitting and fixing the fixing holes 91 (and 92). The assembled wafer supporting device is chemically cleaned with hydrofluoric acid (hereinafter referred to as HF) to perform the cleaning operation again (step 15). The cleaned wafer support device is set in a high temperature heat treatment furnace, the semiconductor wafer is charged, and heat treated together with the semiconductor wafer (step 16).

[0009]

However, in the wafer supporting device assembled and formed by the above-mentioned conventional manufacturing method, since a plurality of members are assembled by fitting or the like, the fitting portion and the joining between the members are joined. There is some play so that a gap 10 as shown in FIG. In addition, since each silicon member is ground according to the predesigned drawing shape, the processing damage and stains on each silicon member are removed by etching with a mixed acid of HF and HNO3. In the gap 1
0 is formed, and wobble occurs after assembly. Due to these wobbles, the bearing grooves 11 (or 21, 61c, 62c, 71c, 72c) of the support body member 1 (or 2, 6, 7) in the wafer supporting apparatus are provided.
There may be scratches around the wafer due to the contact between the semiconductor wafers that are supported very closely inside each other, or the semiconductor wafer may cause a slip on the supporting body member 1 (or 2, 6, 7). Was there. Further, when a robot is used for wafer transfer, there is a problem that transfer troubles occur and production is hindered.

When high temperature heat treatment is performed in an oxidizing atmosphere, an oxide film grows on the wafer supporting device,
If HF is chemically cleaned for the purpose of improving the cleanliness of the apparatus itself, the oxide film is removed by this chemical cleaning, resulting in further wobble. When such wobble becomes larger than a predetermined limit, it becomes difficult to use it as a wafer supporting device, so that the life of the wafer supporting device is short and the replacement frequency is high, and the consumable material cost is high. It was The present invention has been made to solve the above problems, and an object of the present invention is to provide a wafer support device that does not damage semiconductor wafers during high-temperature processing, does not cause slips during bearing, and has a long service life. I am trying.

[0011]

A wafer supporting apparatus according to the present invention is a wafer supporting apparatus formed by assembling a plurality of supporting members, wherein a joint portion formed by assembling each of the supporting members is subjected to CVD (Chemical Vapor). Deposi
tion) is coated with a film. As described above, according to the present invention, since the joint portion between the plurality of support members is covered with the CVD film, the CVD film is inserted into the gap between the joint portions formed by combining the respective support members, and each support member is supported. By making the mutual tight contact with each other, the wobble of the entire apparatus can be eliminated. In particular, since the CVD film is formed thickly in the gap portion formed in the joint portion of each of the plurality of supporting members so as to rise, the CV between the supporting members is increased.
The D film can bond firmly. By eliminating the wobbling of the apparatus as described above, it is possible to suppress the damage to the semiconductor wafer at the time of wafer transfer as much as possible, and it is possible to prevent the reduction of the yield of the wafer due to the slip or the like and to improve the product yield. When the treatment is performed in an oxidizing atmosphere, the CVD film is removed before the oxide film is formed on each support member body,
By forming the CVD film again, it is possible to prevent the wobbling of each support member from increasing. As a result, the service life of the wafer support device itself can be maintained for a long time, and the frequency of replacement can be reduced as much as possible, so that the amount of consumable materials can be reduced.

Further, in the wafer supporting apparatus according to the present invention, the CVD film is a polysilicon film or a silicon carbide film corresponding to the material of the supporting member, or a coating formed on the supporting member, if necessary. It is the same nitride film or oxide film as the film. As described above, in the present invention, the CVD film is made to correspond to the material of the support member or the coating film to form a polysilicon film, a silicon carbide film, a nitride film or an oxide film, so that the heat resistance property is made uniform throughout the member. As a result, the deformation and deterioration of each member can be prevented, and the assembly robustness and stability of the entire device can be further improved.

A method of manufacturing a wafer supporting apparatus according to the present invention is a method of manufacturing a wafer supporting apparatus in which a plurality of supporting members are assembled to form a plurality of supporting members. The assembled wafer supporting device is housed in a reaction chamber under reduced pressure or low pressure, and a bonding film formed by assembling each supporting member by a chemical reaction on the surface of the supporting member is coated with a CVD film. And a process. As described above, according to the present invention, after assembling a plurality of support members, the joint portion of each support member is subjected to CVD in the reaction chamber under reduced pressure or low pressure.
Since the coating is performed with the film, the wobble of the apparatus itself can be more surely prevented by making the CVD film penetrate into the interior of the gap formed in the joint portion of each support member to form the film.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(One Embodiment of the Present Invention) A wafer supporting apparatus according to one embodiment of the present invention will be described together with its manufacturing method with reference to FIG. 5 based on FIGS. 1 and 2. This figure 1
1 is an enlarged view of an assembly structure part and an AA line sectional view thereof when the wafer supporting device shown in FIG. 5 is assembled, and FIG.
3 is an operation flowchart of forming and assembling the wafer support device described in FIG. In the figure, the wafer supporting apparatus according to the present embodiment is assembled with the respective supporting members made of silicon as in the conventional wafer supporting apparatus shown in FIGS. 5 and 6, and the respective supporting members are assembled. Later the whole C
Stored in a VD furnace (not shown) and CVD of polysilicon
This is a configuration in which the formation of a film is added. Each of the supporting members includes a pair of supporting main body members 1 and 2, a pair of side frame members 3 and 4, and holding pieces 51 to 54, which are shown in FIG.
The support body member 1 and the side frame member 3 are held by a holding piece 51.
Only the structure assembled by is shown. The CVD film is formed on each of the supporting members assembled in this manner by covering the entire supporting member with a thin CVD film 100 and forming a thick CVD film 1 at the corners formed between the supporting members.
01 is formed, and the CVD film 102 is formed so as to be raised in the gap 10 existing between the support members.

Next, the operation of forming and assembling the wafer supporting apparatus according to this embodiment based on the above-mentioned structure will be described. First, similarly to the case of the conventional device, the supporting body members 1, 2, the side frame members 3, 4, and the holding pieces 51, 54 are cut out from the ingot of polycrystalline or single crystal silicon (step 1, in FIG. 8). (Corresponding to step 11), each of these members is ground with a predetermined processing accuracy (step 2, corresponding to step 12 in FIG. 8), and each of the ground members is subjected to chemical etching (step 3,).
(Corresponding to step 13 in FIG. 8). In addition, assembling the chemically etched members (step 4,
(Corresponding to step 14 in FIG. 8), the assembled wafer support device is chemically cleaned (step 5,).
(It corresponds to step 15 in FIG. 8).

This chemically cleaned wafer support device forms an oxide film (not shown) on the entire surface by an oxidation device (step 6). The wafer supporting device on which the oxide film is formed is housed in a CVD furnace (not shown) to form the CVD film 100 (step 7). This CVD film 100
Since each member such as the support body members 1 and 2 is formed by cutting out from a silicon ingot, it is desirable to be formed as a silicon film. In addition, the CVD film 1
00 can also be formed into a film with a film thickness of about 2 μm by setting the temperature in the CVD furnace to 620 ° C. This CVD film 1
As shown in FIG. 1 (B), 00 is a thick CVD film 101 at the corner portion formed at the joints between the supporting body members 1 and 2, the side frame members 3 and 4 and the holding pieces 51 to 54.
And is formed as a CVD film 102 that rises in the vicinity of the gap 10 existing in the joint portion between the above-mentioned respective parts. In this way, by forming a particularly thick CVD film 101 or a raised CVD film 102 at the joint between the respective members, the coupling between the respective members becomes stronger, and distortion and wobble of the device itself are prevented. It will be possible.

Further, the wafer supporting device on which the CVD film is formed is housed and set in a high temperature heat treatment furnace (not shown), and the semiconductor wafer is charged and heat treated together with this semiconductor wafer (step 8, in FIG. 8). Corresponding to step 16). In the above-described embodiment, the CVD film 100 is formed (step 7) after the oxide film is formed (step 6) on the assembled wafer supporting apparatus.
It is also possible to form the oxide film after forming the film,
Further, the CVD film 100 can be formed without performing an oxide film forming process.
It is also possible to adopt a configuration in which only the film forming process is performed.

(Other Embodiments of the Present Invention) FIGS. 3 and 4
[FIG. 11] is an enlarged view of a part of an assembling structure of a wafer supporting device according to another embodiment. In FIG. 3, a wafer supporting apparatus according to another embodiment is configured such that the supporting main body member 1 is coupled and locked to the side frame member 3 by the wedge member 55, and each of the coupled and locked members is subjected to CVD.
It is configured to deposit a film. This support body member 1
Is formed by projecting the fitting protrusion 14 at the end, and the fixing hole 14a is formed in the approximate center of the fitting protrusion 14. Further, this support body member 1 is the same as that shown in FIG.
Similar to the support body member 1 described in (1), a supporting groove (not shown) for holding a semiconductor wafer is cut and formed on one side surface of the substantially central portion. The wedge member 55 is formed of a quadrangular prism body formed in a tapered shape, and a cross-sectional shape of a substantially intermediate portion of the quadrangular prism body is substantially the same as an opening shape of a fixing hole formed in the fitting protrusion 14. It is a configuration to match.

In the assembling operation of the wafer supporting apparatus, the fitting protrusion 14 of the supporting body member 1 is attached to the mounting hole 3 of the side frame member 3.
1 and the fixing hole 14 of the fitting protrusion 14 that has been inserted.
The wedge member 55 is fitted in a. In this way, the wedge member 55 is fitted into the fixing hole 14a, and the side frame member 3 is held in the support body member 1 in a barbed shape for assembly. A gap 10 is present at each of the joined portions of the assembled support main body member 1, side frame member 3, and wedge member 55, and in particular, the wedge member 55 and the support main body member 1 formed in a tapered shape are A large tapered gap 10 exists between the side frame member 3.

When the CVD film 100 is formed on the assembled wafer supporting device as in the above embodiment,
A thicker CVD film 101 can be deposited and formed on the joint portion and the joint corner portion of each member. By forming a particularly thick CVD film 101 in the joint portion between the respective members and the portion of the large tapered gap 10 as described above, the coupling between the respective members becomes stronger, and the distortion and wobble of the apparatus itself is prevented. It can be prevented.

In FIG. 4, in a wafer supporting apparatus according to another embodiment, the fitting protrusion 15 of the supporting body member 1 is fitted into the mounting recess 33 of the side frame member 3 to be coupled and locked, and this coupling and locking is performed. A CVD film is formed on each member.
The support body member 1 is formed by projecting a fitting protrusion 15 at an end, and the base of the fitting protrusion 15 is a columnar body having a size slightly narrower than the groove width of the mounting recess 33. The tip portion of is formed of a cylindrical body having a dimension wider than the groove width of the mounting recess 33. This assembled support body member 1
Also, a gap 10 is present at each joint with the side frame member 3.

When the CVD film 100 is formed on the assembled wafer supporting device as in the above embodiment,
A thicker CVD film 101 can be deposited and formed on the joint portion and the joint corner portion of each member. As described above, by forming a particularly thick CVD film 101 in the joint portion between the respective members, the coupling between the respective members becomes stronger, and the distortion and wobble of the device itself can be prevented. In addition to the assembling structure of the support body member 1 and the side frame member 3 in the horizontal wafer supporting device shown in each embodiment, the same can be applied to the vertical wafer supporting device shown in FIG. 7.

Further, in each of the above-described embodiments, the CVD film of polysilicon is formed on the assembled wafer supporting device, but a SiC film can be used in addition to silicon, and each member of the wafer supporting device can be used. The same nitride film or oxide film as the coating film formed above may be used as the CVD film. Further, in each of the above embodiments, a low pressure CVD apparatus or a low pressure CV is used when forming a CVD film.
A D device can be used. By depositing the CVD film under reduced pressure or low pressure in this way, the CVD film can be deposited even deep inside the gap formed between the respective members, and the wobble that occurs between the members can be formed. Can be suppressed more reliably.

[0024]

As described above, according to the present invention, the joint portion between the plurality of support members is coated with the CVD film, so that the CVD film is formed in the gap between the joint portions where the support members are combined. By inserting the support members and bringing the respective support members into a tightly closed state, it is possible to eliminate the wobble of the entire apparatus. In particular, since a CVD film is formed thickly in the gap portion formed at the joint portion of each of the plurality of supporting members so as to rise, C between the supporting members is increased.
The VD film has an effect that it can be firmly bonded. In this way, by eliminating the wobbling of the device, it is possible to suppress the damage to the semiconductor wafer during wafer transfer as much as possible,
The yield of the wafer can be prevented from lowering due to slippage, and the product yield can be improved. Further, in the present invention, the CVD film is made to correspond to the material of the support member or the coating film, and a polysilicon film, a silicon carbide film,
By using a nitride film or an oxide film, the heat resistance characteristics can be made uniform throughout the member, and there is an effect that deformation and deterioration of each member can be prevented and assembly robustness and stability of the entire device can be further improved. Further, in the present invention, after assembling a plurality of support members, the joint portion of each support member is coated with the CVD film in the reaction chamber under reduced pressure or low pressure, so that the joint portion of each support member is formed. By depositing the CVD film to the inside of the gap,
This has the effect that the wobble of the device itself can be prevented more accurately.

[Brief description of drawings]

FIG. 1 is an enlarged view of a part of an assembling structure in the case where a wafer supporting device according to an embodiment of the present invention is assembled and its AA.
It is a line sectional view.

FIG. 2 is an operation flowchart of forming and assembling the wafer support device shown in FIG.

FIG. 3 is an enlarged view of a part of an assembling structure of a wafer supporting device according to another embodiment.

FIG. 4 is an enlarged view of a part of an assembling structure of a wafer supporting apparatus according to another embodiment.

FIG. 5 is an explanatory view of an assembled state of a conventional horizontal assembly type wafer supporting device.

6A and 6B are an enlarged view of a part of an assembling structure and a sectional view taken along the line A'-A 'when the wafer supporting device shown in FIG. 5 is assembled.

FIG. 7 is an assembly state diagram of a conventional vertical assembly-type wafer support device.

FIG. 8 is a flowchart of forming and assembling operations of a conventional wafer supporting apparatus.

[Explanation of symbols]

1, 2, 6, 7 Support body member 3, 4 Side frame member 8 Substrate 9 Top plate 10 Gap 11, 21, 61c, 62c, 71c, 72c Bearing groove 12, 13, 22, 23 Fitting protrusion 12a, 13a , 22a, 23a Hook-shaped groove portion 15 Fitting projection portion 31, 32, 41, 42 Mounting hole 33 Mounting recess 51, ~, 54 Holding piece 55 Wedge member 61, 62, 71, 72 Support rod 61a, 61b, 62a, 62b , 71a, 71b, 7
2a, 72b Fixed protrusion 81, 82, 91, 92 Fixed hole 100, 101, 102 CVD film

Claims (3)

[Claims] 1. A wafer supporting device formed by assembling a plurality of supporting members, wherein a joint portion formed by assembling the supporting members is CV.
A wafer supporting device characterized by being coated with a D film. 2. The wafer supporting apparatus according to claim 1, wherein the CVD film is a polysilicon film or a silicon carbide film corresponding to a material of the supporting member, or a coating film formed on the supporting member. A wafer supporting device, which is the same nitride film or oxide film as the above. 3. A method of manufacturing a wafer supporting apparatus, which is formed by assembling a plurality of supporting members, comprising: an assembling step of assembling the plurality of supporting members; and a wafer supporting apparatus assembled by the assembling step in a reduced pressure or low pressure state. A wafer supporting apparatus, which is provided in a reaction chamber and has a film forming step of coating a CVD film on a bonding portion formed by assembling each supporting member by a chemical reaction on a surface of the supporting member in a vapor phase. Manufacturing method.