WO2012132575A1

WO2012132575A1 - Shower plate, vapor-phase growth apparatus, and vapor-phase growth method

Info

Publication number: WO2012132575A1
Application number: PCT/JP2012/053105
Authority: WO
Inventors: 足立　雄介; 俊範岡田; 坪井　俊樹
Original assignee: シャープ株式会社
Priority date: 2011-03-28
Filing date: 2012-02-10
Publication date: 2012-10-04
Also published as: JP2012216744A

Abstract

A vapor-phase growth apparatus provided with a shower plate (20) for protecting a shower head (10) is characterized in that: the shower plate (20) comprises a center plate (21) with a plurality of plate holes (21a) and a peripheral plate (22) supporting the center plate (21); a space portion (23) is provided between an end face of the center plate (21) and a side face of the peripheral plate (22) facing the end face of the center plate (21); and the space portion (23) is provided with a space equal to or greater than an extension of the center plate (21) due to thermal expansion. Thereby, warping and temperature increase due to thermal expansion of the shower plate (20) can be prevented, and the growth of a product on the shower plate (20) can be restrained, so that a vapor-phase growth apparatus capable of forming a compound semiconductor crystal with stable quality on a process substrate can be provided.

Description

Shower plate, vapor phase growth apparatus and vapor phase growth method

The present invention relates to a shower plate, a vapor phase growth apparatus, and a vapor phase growth method, such as a vertical showerhead type MOCVD (Metal Organic Chemical Vapor Deposition).

Conventionally, in the manufacture of light-emitting diodes, semiconductor lasers, space solar power devices, and high-speed devices using compound semiconductor materials, organometallic gases such as trimethylgallium (TMG) or trimethylaluminum (TMA), ammonia (NH3), MOCVD (Metal Organic Chemical Vapor Deposition) method is used in which a compound semiconductor crystal is grown by introducing a hydrogen compound gas such as phosphine (PH3) or arsine (AsH3) into a growth chamber as a reaction gas that contributes to film formation. .

The MOCVD method is a method in which a compound semiconductor crystal is grown on a substrate by introducing the above-mentioned reaction gas together with a carrier gas into a growth chamber and heating it to cause a gas phase reaction on a predetermined substrate. In the production of compound semiconductor crystals using MOCVD, there is always a high demand for how to secure the maximum yield and production capacity while reducing costs while improving the quality of growing compound semiconductor crystals. Has been.

FIG. 16 shows a schematic configuration of an example of a conventional vertical shower head type MOCVD apparatus used in the MOCVD method. In this MOCVD apparatus, a gas pipe 104 for introducing a reaction gas and a carrier gas from a gas supply source 101 to a growth chamber 103 inside the reaction furnace 102 is connected, and the inside of the growth chamber 103 inside the reaction furnace 102 is connected. A shower head 105 provided with a plurality of gas discharge holes for introducing a reaction gas and a carrier gas into the growth chamber 103 is installed as a gas introduction part at the upper part.

In addition, a susceptor 107 for placing the substrate 106 is installed below the growth chamber 103 so as to face the shower head 105. The susceptor 107 includes a heater 108 for heating the substrate 106, and is rotatable about a rotation shaft 109 by an actuator (not shown).

Furthermore, a gas exhaust unit 110 for exhausting the gas in the growth chamber 103 to the outside is installed at the lower part of the reaction furnace 102. The gas exhaust unit 110 is connected via a purge line 111 to an exhaust gas treatment device 112 for rendering the exhausted gas harmless.

In the case of growing a compound semiconductor crystal in the vertical showerhead type MOCVD apparatus having the above configuration, first, the substrate 106 is set on the susceptor 107, the susceptor 107 is rotated, and the substrate 106 is heated to a predetermined temperature by the heater 108. To do. Thereafter, a reaction gas and a carrier gas (inert gas) are introduced into the growth chamber 103 from a plurality of gas discharge holes provided in the shower head 105.

A specific example of the shower head will be described by exemplifying Patent Document 1 (Japanese Patent Laid-Open No. 8-91989). As shown in FIG. 17, a shower head 200 disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 8-91989) includes a first conduit 202 and a second conduit that separately introduce a plurality of reaction gases into a growth chamber 201. 203 and a cooling chamber 204 for cooling the first conduit 202 and the second conduit 203. According to the shower head 200 of Patent Document 1 (Japanese Patent Laid-Open No. 8-91989), reaction gases are separately introduced into the growth chamber 201, then mixed and homogeneous at a position close to the heated substrate 205. It is described that a mixture can be formed.

However, in the shower head 200 of Patent Document 1 (Japanese Patent Application Laid-Open No. 8-91989), a product due to the gas reacted in the growth chamber 201 is attached to a surface (hereinafter referred to as a shower surface) facing the substrate 205, There arises a problem that the product accumulates to cover the gas discharge hole and clogging occurs. In addition, the product deposited on the shower surface falls on the substrate 205, causing a problem that a defect occurs.

As a means for solving such a problem, for example, a technique disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 11-131239) can be cited. Patent Document 2 (Japanese Patent Laid-Open No. 11-131239) discloses a shower head in which the bottom surface of an upper electrode is covered with an electrode cover 301 as shown in FIG. The electrode cover 301 is provided with a pore 303 having the same diameter so as to overlap the gas ejection pore 302 of the upper electrode, and is fixed to the upper electrode with a screw 304. In the shower head of Patent Document 2 (Japanese Patent Application Laid-Open No. 11-131239), the product is dropped by replacing the electrode cover 301 before the product adhering to the electrode cover 301 is deposited. Can be prevented from being taken in.

Also, as a similar configuration, as shown in FIG. 19, Patent Document 3 (Japanese Patent Publication No. 2002-511529) discloses a shower head 72 that separates a process chamber into an upstream portion and a downstream portion. The shower head 72 is a small aluminum plate having a diameter similar to the diameter of the wafer, and is attached to a large ring 73 in a replaceable manner. The shower head 72 is limited and not larger than the process space. This allows different showerheads to be replaced for use with different size wafers and different processing conditions, and the use of smaller showerheads reduces costs and provides greater process flexibility. The gas flow can be concentrated in the space directly above the substrate.

JP-A-8-91989 Japanese Patent Laid-Open No. 11-13131 Special Table 2002-511529

The shower head suppresses the growth of the reaction product by cooling the periphery of the gas discharge portion as in the cooling chamber 204 of Patent Document 1 (Japanese Patent Laid-Open No. 8-91989), for example. In the shower head disclosed in Document 2 (Japanese Patent Application Laid-Open No. 11-131239), the temperature of the electrode cover 301 disposed facing the substrate to be processed is likely to increase. In particular, the central portion and the surface portion become high temperature and local thermal expansion occurs. appear. Since the periphery of the electrode cover 301 is fixed to the upper electrode with screws 304, as shown in FIG. 20, the center of the electrode cover 301 warps to the lower electrode side, and the contact with the upper electrode is insufficient. It becomes. For this reason, cooling from the upper electrode to the electrode cover 301 is hindered, and the temperature of the electrode cover 301 is increased further.

When the temperature of the electrode cover 301 becomes high, an undesired gas phase reaction of the reaction gas is promoted and reaction products are likely to be deposited. Therefore, there is a problem that the electrode cover 301 must be replaced frequently and the production capacity is lowered. It was. Further, the undesirable gas phase reaction on the electrode cover 301 hinders the gas phase reaction on the substrate to be processed, and there is a problem that the quality of the compound semiconductor crystal, the film forming speed, and the yield are lowered. Further, when the electrode cover 301 is warped, a gap is formed between the upper electrode and the reaction product is deposited on the surface of the upper electrode.

The shower head 72 disclosed in Patent Document 3 (Japanese Patent Publication No. 2002-511529) is also formed in a flat disk shape made of aluminum, and warpage occurs due to the temperature rise of the shower head 72.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to prevent warpage and temperature rise due to thermal expansion of the shower plate, and to suppress the growth of the product on the shower plate, To provide a shower plate, a vapor phase growth apparatus, and a vapor phase growth method capable of forming a compound semiconductor crystal with stable quality on a substrate to be processed.

The shower plate of the present invention is a shower plate for protecting the shower head, and is characterized by including a positioning mechanism for aligning the position of the gas discharge hole of the shower head and the plate hole of the shower plate.

The vapor phase growth apparatus of the present invention is a vapor phase growth apparatus provided with a shower plate for protecting a shower head, and the shower plate includes a central plate having a plurality of plate holes and a peripheral plate for holding the central plate. The space portion is provided between the end surface of the center plate and the side surface of the peripheral plate facing the end surface of the center plate, and the space portion has a space larger than the expansion due to the thermal expansion of the center plate.

In the vapor phase growth method of the present invention, the central plate is arranged in the shower head so that the gas discharge hole of the shower head and the plate hole of the central plate are coaxial, and the peripheral plate holding the central plate is fixed to the shower head. A step of supplying a reaction gas and a carrier gas to the growth chamber through the gas discharge hole and the plate hole, and a step of rotating the substrate facing the shower head and heating with a heater to form a film. The center plate is thermally expanded toward the space provided in the side surface direction thereof to prevent warping of the center plate.

According to the shower plate, the vapor phase growth apparatus, and the vapor phase growth method of the present invention, warpage and temperature rise due to thermal expansion of the shower plate are prevented, and the growth of the product on the shower plate is suppressed, and the substrate to be processed A compound semiconductor crystal with stable quality can be formed on the film.

1 shows an embodiment of a vapor phase growth apparatus according to the present invention, and is a schematic diagram showing an overall configuration of the vapor phase growth apparatus. 2 is a plan view of a shower plate of Example 1. FIG. 3 is a cross-sectional view of the shower plate of Example 1. FIG. It is sectional drawing to which the A section of FIG. 1 was expanded. It is a disassembled perspective view of the shower plate of Example 2. FIG. In the vapor phase growth apparatus which installed the shower plate of Example 3, it is sectional drawing which expands and shows the same area | region as the A section of FIG. FIG. 6 is a schematic diagram illustrating an overall configuration of a vapor phase growth apparatus according to a fourth embodiment. 6 is a plan view of a shower plate of Example 4. FIG. It is sectional drawing of the shower plate of Example 4. FIG. 6 is a cross-sectional view of a positioning pin of Example 4. FIG. It is a perspective view of the positioning pin of Example 4. It is sectional drawing to which the B section of FIG. 6 was expanded. It is a perspective view which shows another form of the shower plate of Example 4. FIG. It is sectional drawing which used another shower plate for the B section of FIG. It is a disassembled perspective view which shows the modification of the shower plate of Example 5. FIG. It is sectional drawing to which the holding | maintenance part in the shower plate of Example 5 was expanded. It is sectional drawing to which the holding | maintenance part in the shower plate of Example 6 was expanded. It is sectional drawing which used the positioning pin for the shower plate of Example 6. FIG. It is sectional drawing which shows schematic structure of the vapor phase growth apparatus which is a prior art. It is sectional drawing which shows an example of the shower head of the vapor phase growth apparatus which is a prior art. It is sectional drawing which shows an example of the shower plate of the vapor phase growth apparatus which is a prior art. It is sectional drawing which shows another example of the shower head of the vapor phase growth apparatus which is a prior art. It is sectional drawing which shows the curvature of the shower plate of the vapor phase growth apparatus which is a prior art.

An embodiment of the present invention will be described with reference to FIG. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts.

FIG. 1 shows an example of a schematic configuration of an MOCVD apparatus 100 as a vapor phase growth apparatus of the present invention. As shown in FIG. 1, the MOCVD apparatus 100 of the present embodiment includes a reaction furnace 1 that isolates the inside from the atmosphere side, and a reaction external space separated by a reaction chamber partition wall 2 in the reaction furnace 1. 3 and reaction chamber 4 are provided. A purge gas supply pipe 5 is connected to the reaction external space 3 and purge gas (N 2 gas, H 2 gas) is introduced. The reaction chamber 4 is provided with a substrate holder 7 on which the substrate 6 to be processed is placed.

The substrate holding unit 7 is provided at one end of the rotation transmitting unit 8 and can be rotated by a rotation mechanism (not shown). A substrate heater 9 for heating the substrate 6 to be processed is provided below the substrate holder 7.

The shower head 10 is detachably disposed on the upper portion of the reaction furnace 1. The reaction furnace 1 and the shower head 10 are sealed by an O-ring 11a, and the inside of the reaction furnace 1 can be exhausted from the gas discharge port 12 to be kept airtight.

The shower head 10 includes a first gas distribution space 13 that is filled with a first gas, and a second gas distribution space 14 that is filled with a second gas different from the first gas, and the first gas distribution space 13 and the second gas. An O-ring 11b is provided between the distribution space 14 and an O-ring 11c is provided between the second gas distribution space 14 and the top plate 14c so that each space can be separated. The airtight state of each space is maintained. In addition, the lower part of the shower head 10 is provided with a refrigerant space 15 filled with refrigerant, and the lower wall surface 10a is cooled by the refrigerant space 15 so that the temperature is controlled to be uniform. .

The shower plate 20 that prevents the product from adhering to the lower wall surface 10 a of the shower head 10 is disposed so as to face the substrate holding portion 7 that holds the substrate 6 to be processed, and is fixed with screws 16. Although details of the shower plate 20 will be described later, the shower plate 20 includes a central plate 21 having a plurality of plate holes 21a and a peripheral plate 22 that holds the central plate 21 and makes contact with the lower wall surface 10a.

When a compound semiconductor crystal is formed on the substrate 6 to be processed, for example, a first gas containing a group III element is introduced into the first gas distribution space 13 from the first gas inlet 13a. After cooling through the plurality of first gas supply pipes 13b penetrating, the reaction gas is introduced into the reaction chamber 4 from the plate holes 21a of the central plate 21 communicating with the gas discharge holes H1 of the first gas supply pipe 13b.

Further, for example, a second gas containing a group V element is introduced into the second gas distribution space 14 from the second gas introduction port 14 a and passes through the plurality of second gas supply pipes 14 b penetrating the refrigerant space 15. After being cooled, the gas is introduced into the reaction chamber 4 from the plate hole 21a of the central plate 21 communicating with the gas discharge hole H2 of the second gas supply pipe 14b.

As described above, the first gas and the second gas are introduced into the reaction chamber 4 separately without being mixed inside the shower head 10, so that the gas phase reaction occurs inside the shower head 10. Is prevented from occurring.

When the substrate 6 to be processed held by the substrate holder 7 is heated to a high temperature by the substrate heater 9 and the first gas and the second gas introduced into the reaction chamber 4 reach the substrate 6 to be processed at a high temperature. The gas phase reaction is promoted, and a compound semiconductor thin film is formed on the substrate 6 to be processed. The reaction gas that has passed over the substrate 6 to be processed is discharged from the gas discharge port 12 and made harmless by an exhaust gas processing apparatus (not shown).

Next, the shower plate 20 which is a characteristic structure of the present invention will be described in detail with reference to FIGS. 2A is a plan view of the shower plate 20 viewed from the substrate 6 to be processed, and FIG. 2B is a cross-sectional view taken along the line BB in FIG. 2A. FIG. 3 is an enlarged cross-sectional view of part A of the MOCVD apparatus 100 shown in FIG.

2, the shower plate 20 includes a central plate 21 having a plurality of plate holes 21a and a peripheral plate 22 that holds the central plate 21 and makes contact with the lower wall surface 10a. The central plate 21 is provided with a plurality of plate holes 21a so as to correspond to the gas discharge holes H1 and H2 of the shower head 10, and each plate hole 21a is formed in the gas discharge holes H1 and H2 with respect to the shower head 10. Arranged to overlap. Accordingly, the gas discharge holes H1 and H2 and the plate holes 21a are coaxial and can introduce the reaction gas into the reaction chamber 4.

The peripheral plate 22 holds the end 21b of the central plate 21 in the periphery, and brings the central plate 21 into contact with the lower wall surface 10a of the shower head 10. The peripheral plate 22 includes a screw hole 22a for fixing the peripheral plate 22 to the lower wall surface 10a of the shower head 10 with a screw 16, and a holding portion 22b for holding the central plate 21 on a side surface facing the end surface of the central plate 21. Is formed in a notch shape.

In a state where the end portion of the central plate 21 is held by the holding portion 22b of the peripheral plate 22, a predetermined space is provided between the end surface of the central plate 21 and the side surface 22c of the peripheral plate 22 facing the end surface 21c of the central plate 21. A portion 23 is provided. This space portion 23 is a space equal to or larger than the extension when the central plate 21 is thermally expanded.

The peripheral plate 22 is fixed to the lower wall surface 10a of the shower head 10 with screws 16 while holding the central plate 21 disposed so that the plate holes 21a overlap the gas discharge holes H1 and H2.

FIG. 3 is an enlarged view of part A in the vapor phase growth apparatus 100 shown in FIG. 1 and shows a state in which the shower plate 20 is attached to the lower wall surface 10 a of the shower head 10. As shown in FIG. 3, the portion where the shower plate 20 is divided into a central plate 21 and a peripheral plate 22 is outside the substrate holding portion 7 (hereinafter referred to as a heating region) heated to a high temperature during film formation (hereinafter referred to as a heating region). It is arranged in a region (referred to as a non-heated region).

In the shower plate 20, the central plate 21 is arranged in the heating region and the temperature rises at the time of film formation, but the peripheral plate is arranged in the non-heating region and is kept at a lower temperature than the central plate 21, A temperature gradient is generated between the central plate 21 and the peripheral plate 22. Here, since the shower plate 20 is divided into a central plate 21 and a peripheral plate 22, heat conduction from the central plate 21 to the peripheral plate 22 is suppressed, and the temperature distribution of the central plate 21 and the peripheral plate 22 is different. It becomes small and the curvature by a part of plate becoming high temperature and thermally expanding can be prevented.

Further, as shown in FIG. 3, the central plate 21 is not directly fixed to the lower wall surface 10a of the shower head 10, and is held by the frictional force of the contact surface of the first holding portion 22b of the peripheral plate 22. Thus, when the center plate 21 rises in temperature and thermally expands, the extension can overcome the frictional force and move to the space 23. For this reason, internal stress due to thermal expansion is not applied to the center plate 21, and it is possible to prevent the center plate 21 from warping.

Thus, the center plate 21 is prevented from warping due to thermal expansion even during film formation, and is held in contact with the lower wall surface 10a of the shower head 10, so that the temperature can be controlled to a low temperature. Therefore, the growth of the product on the surface of the central plate 21 is suppressed, and the decrease in the film forming rate on the substrate 6 to be processed is prevented. Further, clogging of the product in the plate hole 21a and dropping of the product on the substrate 6 to be processed are less likely to occur, and it becomes unnecessary to frequently replace the central plate 21, thereby improving the production capacity of the vapor phase growth apparatus. be able to.

Further, in the divided portion of the central plate 21 and the peripheral plate 22, the end portion of the central plate 21 and the first holding portion 22b of the peripheral plate 22 overlap so that the shower head lower wall surface 10a does not look into the substrate 6 to be processed. Therefore, the backflow of the reaction gas from the reaction chamber 4 to the shower head 10 side is prevented, and the product is not attached to the lower wall surface 10 a of the shower head 10. For this reason, maintenance such as cleaning for the shower head 10 can be reduced.

In the first embodiment, a step is provided at the end of the central plate 21 and overlapped with the holding portion 22b of the peripheral plate 22, but the end of the central plate 21 has a shape without a step. May be.

In addition, the end of the central plate 21 and the holding portion 22b of the peripheral plate 22 are provided with alignment markers and unevenness toward the central portion so that the plate hole 21a can be easily aligned with the gas discharge holes H1 and H2. An engaging portion or the like may be provided.

FIG. 4 is an exploded perspective view of the shower plate 20 of the second embodiment. In the second embodiment, the configuration of the central plate 21 or the peripheral plate 22 is different, and the other configurations are the same as those of the first embodiment, and thus detailed description thereof is omitted. As shown in FIG. 4, the central plate 21 is divided into two at the central portion in the radial direction, and the notches 21 d formed at the respective divided ends are fitted so that the side surfaces are separated from each other and have a gap. Thus, a first fitting portion 24 is provided.

Further, the peripheral plate 22 is divided into four parts, and the notch parts 22d formed at the respective divided ends are fitted so as to separate the side surfaces from each other and have a gap, thereby providing the second fitting part 25. It has been. In FIG. 4, the screw holes 22a of the peripheral plate 22 are omitted, but at least one screw hole 22a is provided in each plate piece.

According to the above configuration, when the center plate 21 expands due to thermal expansion, the extension is absorbed by the space portion 23 and also by the gap provided in the first fitting portion 24. Even if the extension of the plate 21 increases, warping can be prevented.

Further, when the peripheral plate 22 expands due to thermal expansion, the extension is absorbed by the space portion 23 and also by the gap provided in the second fitting portion 25. Warpage can be prevented even when the size of the film increases.

Further, since the central plate 21 and the peripheral plate 22 are divided into a plurality of plate pieces, the size of the component (plate piece) can be reduced as compared with the case where the plate is produced as one member. As a result, even when the apparatus is increased in size, an effect of reducing the manufacturing cost of the central plate 21 and the peripheral plate 22 can be obtained.

Further, the first fitting portion 24 of the central plate 21 is shielded so that the contact surfaces of the notch portions 21d overlap each other and the shower head lower wall surface 10a is not looked into from the processed substrate 6 side. The reaction gas introduced into the chamber 4 is prevented from flowing back to the shower head 10 side, and the product growth on the lower wall surface 10a of the shower head 10 is prevented. For this reason, maintenance such as cleaning for the shower head 10 can be reduced.

Similarly, the second fitting portion 25 of the peripheral plate 22 is also shielded so that the contact surfaces of the notch portions 22d overlap each other and the shower head lower wall surface 10a does not look into the substrate 6 to be processed. The reaction gas introduced into the reaction chamber 4 is prevented from flowing back to the shower head 10 side, and the product growth on the lower wall surface 10a of the shower head 10 is prevented. For this reason, maintenance such as cleaning for the shower head 10 can be reduced.

In addition, although the peripheral plate 22 demonstrated the structure divided | segmented into 4 parts, the structure divided | segmented into 4 parts or more may be sufficient, and the expansion | extension by thermal expansion can be absorbed equally by increasing the number of division | segmentation. .

FIG. 5 shows a vapor phase growth apparatus according to the third embodiment, and is an enlarged cross-sectional view of the same part as part A in FIG. In the third embodiment, the configuration of the holding portions of the end portion 21b of the central plate 21 and the holding portion 22b of the peripheral plate 22 is different, and the other configurations are the same as those of the first embodiment, so detailed description thereof is omitted. .

As shown in FIG. 5, the vapor phase growth apparatus according to the third embodiment is provided with a lubrication member 26 having lubricity on the contact surface between the end 21 b of the central plate 21 and the holding portion 22 b of the peripheral plate 22. It is a feature. The lubrication member 26 makes the frictional force at the contact surface between the end portion 21b of the central plate 21 and the holding portion 22b of the peripheral plate 22 uniform, and smoothly moves the extension portion of the central plate 21 thermally expanded to the space portion 23. Can be made. For this reason, the end portion 21b of the central plate 21 is caught on the contact surface with the holding portion 22b, and the central plate 21 moves in an uneven manner, so that the gas discharge holes H1 and H2 and the plate hole 21a are displaced to block the holes. It is possible to prevent the space 23 from being reduced and the extension due to thermal expansion from being absorbed.

In addition, the provision of the lubricating member 26 increases the thermal resistance between the end portion 21b of the central plate 21 and the first holding portion 22b of the peripheral plate 22, and from the central plate 21 disposed in the heating region. Since the heat transfer to the peripheral plate 22 arranged in the non-heated region is divided, the entire temperature of the central plate 21 and the peripheral plate 22 can be kept more uniform, and a part of the plate thermally expands locally. It is possible to prevent warping.

The material of the lubricating member 23 is preferably a material composed of any one of high purity carbon, pyrolytic carbon coating carbon, pyrolytic carbon, and boron nitride. These materials have lubricity, corrosion resistance against H2 and NH3 gas, heat resistance against heat, and the like, so they are suitable for the internal environment of the reactor 1 of the vapor phase growth apparatus and are provided with the shower plate 20. It is possible.

The fourth embodiment includes a positioning mechanism for aligning the gas discharge holes H1 (H2) of the shower head 10 and the plate holes 21a of the central plate 21 in the MOCVD apparatus 100 of the first embodiment. 1 are denoted by the same reference numerals and detailed description thereof is omitted.

FIG. 6 is a diagram illustrating a schematic configuration of the MOCVD apparatus 100 according to the fourth embodiment. As shown in FIG. 6, in the MOCVD apparatus 100 according to the fourth embodiment, the central plate 21 is provided with positioning pins 27 for aligning the gas discharge holes H <b> 1 and H <b> 2 of the shower head 10 and the plate hole 21 a of the central plate 21. .

FIG. 7A is a plan view of the shower plate 20 according to the fourth embodiment, and shows a position where the positioning pin 27 is provided on the central plate 21. As shown in FIG. 7A, the positioning pin 27 is installed near the center of the center plate 21.

FIG. 7B is a cross-sectional view of the shower plate 20 and shows a state where the positioning pins 27 are installed on the central plate 21. The positioning pin 27 is inserted into the plate hole 21a of the central plate 21 from the reaction chamber side, and the pin portion 28 at the tip protrudes from the plate hole 21a to the shower head side. By fitting the protruding pin portion 28 into the gas discharge hole H1 (or H2) of the shower head 10, the positions of the plate hole 21a and the gas discharge holes H1 and H2 can be easily aligned. Note that the positioning pin 27 may be used to align the position and may be fixed to the gas discharge hole H1 (or H2).

As shown in FIG. 7A, the positioning pin 27 is installed in the vicinity of the central portion of the central plate 21, so that the central plate 21 is not prevented from expanding outward due to thermal expansion. The center plate 21 can be prevented from warping.

Further, the positioning pin 27 is fixed to the gas discharge hole H1 (or H2), or is installed at at least two places on the central plate 21, thereby restraining the movement of the central plate 21 in the rotational direction, It is possible to prevent displacement between the gas discharge holes H1 and H2 and the plate hole 21a accompanying the rotation of the central plate 21.

8A is a sectional view of the positioning pin 27, and FIG. 8B is a perspective view of the positioning pin 27. FIG. The positioning pin 27 is a bolt-shaped member that is integrally formed in the order of the locking screw 29 and the head portion 30 from the pin portion 28 at the tip. Further, the positioning pin 27 has a through hole 31 penetrating from the pin portion 28 through the central shaft portion of the head 30.

The locking screw 29 is male threaded, and the locking screw 29 can be screwed to the plate hole 21a by machining the plate hole 21a of the central plate 21 with a female screw. In addition, for example, a hexagonal shape is used so that the head 30 of the positioning pin 27 can be gripped with a tool or the like when screwing. The head 30 is not limited to this shape, and may be a slit shape, a two-chamfered shape, or the like, as long as it is a shape that matches the fastening tool.

FIG. 9 is an enlarged view of the main part B of FIG. 6, and shows a state in which the plate hole 21 a of the central plate 21 and the gas discharge hole H 1 (or H 2) of the shower head 10 are aligned by the positioning pin 27. Show. Since the positioning pin 27 is screwed to the center plate 21 and the pin portion 28 protrudes from the center plate 21, the plate portion 21a is inserted into the gas discharge hole H1 (or H2) as a positioning mechanism. And the discharge hole H1 (or H2) can be aligned.

The plate hole 21a in which the positioning pin 27 is installed and the gas discharge hole H1 (H2) are not blocked by each other because the positioning pin 27 has the through hole 31, and the positioning pin 27 is installed. The reaction gas can also be introduced into the reaction chamber 4 at the places where the operation is performed.

Further, since the reaction gas flows through the through hole 31 and is cooled, the temperature rise in the vicinity of the positioning pin 27 can be suppressed. For this reason, it is possible to prevent the adhesion of the product without causing a gas phase reaction due to a temperature rise.

In addition, since the hole diameter of the through-hole 31 is smaller than the hole diameter of the gas discharge hole H1 (H2), the flow velocity of the reaction gas changes at the tip of the pin portion 28, and the reaction gas flow may be stagnation. Such stagnation of the reaction gas generates a product inside the shower head 10.

For this reason, as shown in FIGS. 8A and 8B, the through hole 31 is provided with a tapered portion 33 in which the diameter of the through hole 31 increases toward the tip 32 of the pin portion 28. By having the taper portion 33, the change in the hole diameter from the gas discharge hole H1 (H2) toward the through hole 31 is reduced, so that the stagnation of the flow of the reaction gas at the tip 32 of the pin portion 28 is eliminated, and the shower head It is possible to prevent the product from adhering to the inside.

FIG. 10 is a perspective view showing a structure in which the center plate 21 and the positioning pins 27 are integrally formed as another form of the positioning pins 27. As shown in FIG. 10, it is also possible to integrally form the pin portion 28 on the central plate 21 by machining or welding. However, as described above, it is more advantageous in terms of manufacturing cost and manufacturing accuracy that the central plate 21 and the positioning pin 27 are formed separately.

Further, as another form of the positioning pin 27, the positioning pin 27 can be provided on the shower head 10 side. For example, the first gas supply pipe 13b (second gas supply pipe 14b) is protruded from the lower wall surface 10a of the shower head 10, the diameter of the plate hole 21a of the central plate 21 is enlarged, and the protruding first gas supply pipe 13b is plate-shaped. By fitting into the hole 21a, alignment and misalignment can be prevented in the same manner as the positioning pin 27 described above.

FIG. 11 is a cross-sectional view showing a structure in which a counterbore part (concave part) 34 is provided in the central plate 21 and the protrusion of the head 30 of the positioning pin 27 is eliminated. As shown in FIG. 11, a counterbore part 34 may be formed at a location where the positioning pin 27 of the central plate 21 is installed, and the head 30 of the positioning pin 27 may be placed in the counterbore part 34. Thus, by flattening the surface of the central plate 21, it is possible to prevent the head 30 of the positioning pin 27 from protruding and obstruct the flow of the reaction gas in the reaction chamber 4. The film forming rate, film uniformity, reproducibility, etc. can be improved.

Example 5 is a shower plate 20 suitable for a large MOCVD apparatus 100 that processes a plurality of substrates to be processed. The shower plate 20 described in the second embodiment is different in the structure of division, and the other configurations are the same as those in the second embodiment, so detailed description thereof is omitted.

FIG. 12 shows an exploded perspective view of the shower plate 20 of the fifth embodiment. As the MOCVD apparatus 100 becomes larger, the shower plate 20 also becomes larger. When the shower plate 20 is manufactured or when the attached product is cleaned, it is desirable that the shower plate 20 can be divided into small pieces so as to be easily handled.

For this reason, the shower plate 20 of the fifth embodiment has a structure in which the shower plate 20 is divided into three or more pieces and is composed of a plurality of small fan-shaped plate pieces. Also, each plate piece is divided into equal sizes to reduce variation in the amount of thermal expansion of each plate piece and prevent the center plate 21 from being unevenly warped and losing flatness. Yes.

As shown in FIG. 12, the central plate 21 has, for example, a structure in which the central plate 21 is divided into four in the radial direction from the center. When the center plate 21 is equally divided into three or more from the center, the center side of each plate piece is bent downward, and a gap is easily generated between the center plate 21 and the shower head 10. For this reason, each plate piece is provided with a locked portion 35 on the center side, and the shower head 10 is provided with a locking portion 40 for locking the locked portion 35 of each plate piece.

The locked portion 35 is formed with a concave groove portion 36 having a U-shaped cross section on the end face on the center side of each plate piece. Moreover, the latching | locking part 40 consists of a cylindrical body which has the convex edge part 41, and is being fixed to the center part of the shower head lower wall surface 10a with a screw | thread (not shown).

FIG. 13 is a cross-sectional view showing a state where the locked portion 35 of each plate piece is locked to the locking portion 40. By fitting the convex edge portion 41 of the locking portion 40 inside the recessed groove portion 36 of the locked portion 35, the product is prevented from adhering to the locking portion 40, and each of the central plates 21. The plate piece can be locked by being brought into contact with the shower head 10 at the center side.

In the sixth embodiment, like the shower plate 20 of the fifth embodiment, the central plate 21 is divided into three or more pieces and is composed of a plurality of small fan-shaped plate pieces. The to-be-latched part 35 is formed. The shower head 10 is provided with a locking portion 40 that locks the locked portion 35 of each plate piece. Here, the structure of the to-be-latched part 35 and the latching | locking part 40 differs from Example 5, and since it is the same as that of Example 5 about another structure, detailed description is abbreviate | omitted.

FIG. 14 shows a cross-sectional structure of the locked portion 35 and the locking portion 40 of the sixth embodiment. As for the to-be-latched part 35, the through-hole 37 is formed in the center side edge part of each plate piece. In addition, the locking portion 40 is formed with a screw hole 42 corresponding to the through hole 37 in the central portion of the shower head lower wall surface 10a. Then, the through hole 37 of each plate piece is locked to the screw hole 42 of the shower head 10 with a screw 43, whereby the center side of each plate piece is held in contact with the shower head 10.

With the structure shown in Example 6, the locked portion 35 and the locking portion 40 can be easily manufactured, and a structure in which maintenance such as cleaning and repair can be easily performed can be achieved.

In the sixth embodiment, the screw 43 that locks the through hole 37 of the locked portion 35 may be formed in the recess 38 so as not to protrude.

Further, the plate hole 21a of the plate piece is used for the through hole 37 as the locked portion 35, and the screw hole 42 is provided in the gas discharge hole H1 (H2) as the locking portion 40, so that the through hole 31 shown in the fourth embodiment is used. It may be locked by a screw 43 such as a positioning pin 27 having

FIG. 15 shows a state in which the plate hole 21a serving as the locked portion 35 is locked to the gas discharge hole H1 having the locking portion 40 by the positioning pin 27 having the through hole 31 and threaded. In this case, when the reaction gas flows into the through hole 31 of the locked positioning pin 27, the locked portion 35 and the locking portion 40 are cooled, and the temperature rise can be suppressed.

As mentioned above, although each Example was described, it cannot be overemphasized that the reactor 1, the shower plate 20, and other members which comprise the MOCVD apparatus 100 are not limited to the structure shown in each Example in this invention.

For example, the shower plate 20 desirably has a thermal conductivity of 100 W / (m · K) or more and a thermal expansion coefficient of 6 × 10E-6 / ° C. or less. When the thermal conductivity is 100 W / (m · K) or more, the surface temperature of the shower plate 20 is kept low, and the temperature difference from the back surface becomes small. Further, when the thermal expansion coefficient is 6 × 10E−6 / ° C. or less, thermal expansion becomes difficult and the amount of elongation becomes small. For this reason, the warp of the shower plate 20 is prevented, the growth of the product on the surface of the shower plate 20 is suppressed, and the film formation rate, film uniformity and film reproducibility on the substrate 6 to be processed are ensured. An obtained vapor phase growth apparatus and vapor phase growth method can be provided.

The material of the central plate 21 and the peripheral plate 22 constituting the shower plate 20 is preferably any of molybdenum or tungsten, high purity carbon, SiC coated carbon, TaC coated carbon, pyrolytic carbon coated carbon, and pyrolytic carbon. . Since these materials are materials having high thermal conductivity and low thermal expansion coefficient, they have the effect of preventing the warp of the shower plate 20 as described above, and have corrosion resistance against H2 and NH3 gas. The durability of 20 can be improved. For this reason, since the replacement frequency of the shower plate 20 can be reduced, tact time reduction and cost reduction can be achieved.

Further, like the shower plate 20, the material of the positioning pin 27 is preferably any of molybdenum or tungsten, high purity carbon, SiC coated carbon, TaC coated carbon, pyrolytic carbon coated carbon, and pyrolytic carbon. These materials are materials having a high thermal conductivity and a low thermal expansion coefficient, and since there is no difference in thermal expansion between the positioning pin 27 and the shower plate 20, the positioning pin 27 is loosened or the shower plate 20 is distorted. It is prevented. Moreover, since it has corrosion resistance with respect to H2 and NH3 gas, durability of the positioning pin 27 can be improved. For this reason, since the replacement frequency of the positioning pin 27 can be reduced, the tact time can be shortened and the cost can be reduced.

In addition, the present invention brings about a remarkable effect even in a large apparatus including a multi-furnace furnace that processes a plurality of substrates to be processed. For example, in a single furnace that processes one 6-inch substrate, the diameter of the shower head 10 and the shower plate 20 is about 150 mm, but in a multi-furnace furnace that processes seven 6-inch substrates, it is arranged most closely. Even so, the diameter reaches three times 450 mm, and the extension due to the thermal expansion of the shower plate 20 increases three times. Further, when there is a temperature distribution in the shower plate 20, the contribution of deformation due to thermal expansion is further increased.

According to the present invention, even in a large apparatus in which the diameters of the shower head 10 and the shower plate 20 are increased, the warp of the shower plate 20 is prevented and the surface temperature of the shower plate 20 does not become high. The growth of the formed product can be suppressed, and the film formation rate, film uniformity, and film reproducibility on the substrate 6 can be ensured.

Furthermore, it should be considered that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 reaction furnace, 4 reaction chamber (growth chamber), 6 substrate to be processed, 7 substrate holder, 9 substrate heater, 10 shower head, 20 shower plate, 21 center plate, 21a plate hole, 22 peripheral plate, 22a screw hole , 22b holding part, 23 space part, 24 first fitting part, 25 second fitting part, 26 lubrication member, 27 positioning pin, 35 locked part, 40 locking part, 100 MOCVD apparatus Phase growth equipment).

Claims

A vapor phase growth apparatus including a shower plate (20) for protecting the shower head (10),
The shower plate (20) includes a central plate (21) having a plurality of plate holes (21a) and a peripheral plate (22) holding the central plate (21).
A space (23) is provided between the end surface of the central plate (21) and the side surface of the peripheral plate (22) facing the end surface of the central plate (21).
The vapor phase growth apparatus characterized in that the space portion (23) includes a space portion that is longer than the expansion due to thermal expansion of the central plate (21).
The vapor phase growth apparatus according to claim 1, wherein a holding portion (22b) for holding an end portion of the central plate (21) is provided on a side surface of the peripheral plate (22).
The gas phase according to claim 2, wherein a lubricating member (26) is provided at a portion of the peripheral plate (22) where the holding portion (22b) and the central plate (21) are in contact with each other. Growth equipment.
4. The vapor phase growth apparatus according to claim 3, wherein the lubricating member (26) is made of a material containing any one of high purity carbon, pyrolytic carbon, and boron nitride.
The said center plate (21) or the said peripheral plate (22) consists of a some plate piece, and each plate piece has a fitting part, It has overlapped with the said fitting part, The Claim 1 characterized by the above-mentioned. The vapor phase growth apparatus described.
The central plate (21) is composed of a plurality of plate pieces divided into three or more,
The to-be-latched part (35) formed in the center side of these plate pieces is latched by the latching | locking part (40) provided in the said shower head (10), 5. The vapor phase growth apparatus according to 5.
7. The vapor phase growth apparatus according to claim 6, wherein each of the plurality of plate pieces has a fan shape divided substantially equally.
The locking portion (40) is composed of a cylindrical body having a convex edge portion,
The locked portion (35) is a concave groove formed on one end surface of the plate,
The vapor phase growth apparatus according to claim 6, wherein the convex edge portion and the concave groove portion are fitted and locked.
The central plate (21) is composed of a plurality of plate pieces divided into three or more,
6. The vapor phase growth according to claim 5, wherein a through-hole formed in a center side of the plurality of plate pieces is screwed into a screw hole provided in the shower head (10). apparatus.
The said through hole is a plate hole (21a) of the said plate piece, It is latched by the screw hole provided in the gas discharge hole of the said shower head (10) with the screw which has a through hole. Item 10. The vapor phase growth apparatus according to Item 9.
The central plate (21) or the peripheral plate (22) is made of a material containing any one of molybdenum, tungsten, high-purity carbon, SiC-coated carbon, TaC-coated carbon, and pyrolytic carbon. The vapor phase growth apparatus according to claim 1.
The vapor phase growth apparatus according to claim 1, further comprising a positioning mechanism for aligning the gas discharge holes of the shower head (10) and the plate holes (21a) of the central plate (21).
The positioning mechanism is a protrusion provided on the central plate (21),
The vapor phase growth apparatus according to claim 12, wherein the protrusion is fitted into the gas discharge hole.
14. The vapor phase growth apparatus according to claim 13, wherein the projection is provided in the vicinity of the center of the center plate (21).
The vapor phase growth apparatus according to claim 13, wherein the protrusion is a positioning pin (27) fixed to a plate hole (21a) of the central plate (21).
The vapor phase growth apparatus according to claim 13, wherein the protrusion is formed integrally with the central plate (21).
14. The vapor phase growth apparatus according to claim 13, wherein the protrusion has a through hole in a protruding direction.
18. The vapor phase growth apparatus according to claim 17, wherein the through hole has a tapered portion on a protruding side.
A shower plate (20) for protecting the shower head (10),
A shower plate (20) comprising a positioning mechanism for aligning the gas discharge holes of the shower head (10) and the plate holes (21a) of the shower plate (20).
The positioning mechanism is a protrusion provided on the shower plate (20),
The shower plate according to claim 19, wherein the protrusion is fitted into the gas discharge hole.
21. The shower plate according to claim 20, wherein the protrusion is provided near the center of the shower plate (20).
The shower plate according to claim 21, wherein the protrusion is a positioning pin (27) fixed to a plate hole (21a) of the shower plate (20).
23. The shower plate according to claim 22, wherein the projecting portion is fixed to the positioning hole (27) which is male threaded in the plate hole (21a) which is female threaded.
The central plate (21) is arranged in the shower head (10) so that the gas discharge hole of the shower head (10) and the plate hole (21a) of the central plate (21) are coaxial, and the central plate (21 ) Securing a peripheral plate (22) holding the showerhead (10);
Supplying a reaction gas and a carrier gas to the growth chamber through the gas discharge hole and the plate hole (21a);
Rotating the substrate facing the shower head (10) and heating the substrate with a heater to form a film,
At the time of heating, the center plate (21) is thermally expanded toward a space provided in a side surface direction thereof, thereby preventing the warp of the center plate (21).
Between the end surface of the central plate (21) and the side surface of the peripheral plate (22) facing the end surface of the central plate (21), a space portion that is longer than the extension due to thermal expansion of the central plate (21) is provided. The vapor phase growth method according to claim 24, further comprising a step.