JP2011012331A - Vapor deposition apparatus and vapor deposition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that a high-temperature region and a low-temperature region are formed on a shower plate due to an influence of a heating region of a substrate-heating heater, a flaky product that easily exfoliates is formed on the surface of the shower plate at the low-temperature region (non-heated region) in an outer peripheral portion of the shower plate, and the product deposits on a substrate to be treated as a contaminant and causes the deterioration of the quality and uniformity of the film.SOLUTION: This vapor deposition apparatus is constituted by: arranging a space in the outside of a region of the shower plate opposing to a substrate-holding member and in the contacting face between a shower head and the shower plate; and providing a plurality of through-holes that communicate with the inside of a reaction chamber, in a region part in which the space of the shower plate has been arranged, and that introduce a purge gas to the reaction chamber therethrough. Therefore, the apparatus can pass a source gas which exists on the surface of the shower plate in the non-heated region, toward a gas exhaust port side, and further can make a stagnant region hardly formed at a corner. Thus, the apparatus reduces the product to be formed on the surface of the shower plate, and secures the uniformity and reproducibility of the film on the substrate to be treated.

Description

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

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), and ammonia (NH ₃ ) MOCVD (Metal Organic Chemical Vapor Deposition) method in which a compound semiconductor crystal is grown by introducing a hydrogen compound gas such as phosphine (PH ₃ ) or arsine (AsH ₃ ) into the growth chamber as a source gas contributing to film formation It has been.

  The MOCVD method is a method in which a compound semiconductor crystal is grown on a substrate by introducing the above-described source gas into a growth chamber together with a carrier gas 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. 7 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 103 for introducing a reaction gas and an inert gas from a gas supply source 102 to a growth chamber 111 inside the reaction furnace 101 is connected to the growth chamber 111 inside the reaction furnace 101. A shower plate 110 having a plurality of gas discharge holes for introducing a reaction gas and an inert gas into the growth chamber 111 is installed as a gas introduction part.

  In addition, a rotating shaft 112 that can be rotated by an actuator (not shown) is installed in the center of the lower portion of the growth chamber 111 of the reaction furnace 101, and a susceptor 108 is attached to the tip of the rotating shaft 112 so as to face the shower plate 110. ing. A heater 109 for heating the susceptor 108 is attached to the lower part of the susceptor 108.

  Further, a gas exhaust unit 104 for exhausting the gas in the growth chamber 111 inside the reaction furnace 101 to the outside is installed at the lower part of the reaction furnace 101. This gas exhaust unit 104 is connected via a purge line 105 to an exhaust gas treatment device 106 for rendering the exhausted gas harmless.

  When a compound semiconductor crystal is grown in the vertical showerhead type MOCVD apparatus having the above configuration, first, the substrate 107 is set on the susceptor 108, the susceptor 108 is rotated by the rotation of the rotating shaft 112, and the heater 109 is heated. The substrate 107 is heated to a predetermined temperature via the susceptor 108. Thereafter, a reactive gas and an inert gas are introduced into the growth chamber 111 inside the reaction furnace 101 from a plurality of gas discharge holes formed in the shower plate 110.

  As a method of forming a thin film by introducing a plurality of reaction gases and reacting them on the substrate 107, conventionally, a plurality of gases are mixed in a shower head and the substrate is discharged from a gas discharge hole provided in a large number in the shower plate 110. A method of ejecting a reactive gas to 107 was adopted.

  However, in this method, the surface of the shower plate 110 is heated due to the influence of heat from the substrate 107 and the susceptor 108, so that some chemical reaction proceeds on the surface of the shower plate 110. As a result, a product is formed on the surface of the shower plate 110, and the problem that the gas discharge holes of the shower plate 110 are clogged with the product, and the deposits on the surface of the shower plate 110 are on the substrate 107. This causes a problem that the product falls and becomes defective.

  In order to solve this problem, for example, as shown in FIG. 8, in the reaction vessel 200 disclosed in Patent Document 1, the growth chamber 203 is separated in a state where a plurality of reaction gases are separated by individual shower head conduits 201 and 202. A method is shown in which a cooling chamber 204 for cooling the respective showerhead conduits 201 and 202 is provided on the growth chamber 203 side. In this reaction vessel 200, since a plurality of reaction gases are separately introduced, gas mixing is small in the vicinity of the shower surface, the shower surface can be cooled, and vapor phase growth in the vicinity of the shower surface hardly occurs. For this reason, product adhesion to the shower surface can be suppressed.

  By the way, in order to grow a thin film having a uniform film thickness distribution and composition ratio distribution on a substrate with good productivity and reproducibility, it is necessary to perform a gas phase reaction of the reaction gas on the substrate with a uniform temperature distribution.

  In addition, it is necessary to improve the operating rate by preventing the source gases from reacting with each other before reaching the substrate to generate additional compounds and preventing impurities from being mixed into the thin film.

  In this regard, in the reaction vessel 200 shown in FIG. 8 disclosed in the above-mentioned Patent Document 1, the product adhesion on the shower surface is suppressed, but since the gas phase reaction occurs due to mixing by diffusion of the raw material gas, Not a little product will adhere to the surface, and clogging will occur if it is not cleaned regularly. Further, the attached product falls onto the substrate to be processed, and impurities are mixed into the thin film. Further, in the case of cleaning, since the shower head 205 itself is removed for cleaning, the growth chamber 203 must be opened to the atmosphere at the time of replacement, resulting in a decrease in operating rate.

  Therefore, in the plasma CVD film forming apparatus disclosed in Patent Document 2, as shown in FIG. 9, a shower plate 301 having pores corresponding to a shower head is used, and the shower plate is fixed by screwing 302, and the shower surface. The method of covering is shown. Deposits are deposited on the cover due to the presence of the shower plate 301, and by periodically replacing the shower plate 301, the occurrence of defects such as dropping of the deposits on the substrate is prevented.

  As described above, in the plasma CVD film forming apparatus disclosed in Patent Document 2, by attaching the shower plate 301 to the shower surface, even if deposits are generated, it can be easily handled by simply replacing the shower plate 301. As compared with the case where the shower head itself is washed, the decrease in the operation rate is also small.

JP-A-8-91989 (published on April 9, 1996) Japanese Patent Laid-Open No. 11-13131 (published on May 18, 1999)

  However, when the method disclosed in the above-mentioned conventional Patent Document 2 is used in the method disclosed in the above-mentioned Conventional Patent Document 1, the region where the temperature of the shower plate is high and the region where the temperature is low due to the influence of the heating region of the substrate heater. In the region where the temperature is high, a strong product is formed on the surface of the shower plate, but in the region where the temperature is low in the outer peripheral portion, a product that easily peels off in the form of flakes is formed on the surface of the shower plate. End up. Thereafter, the flaky product peels off and adheres to the substrate to be processed as contamination, resulting in a problem that the film quality and uniformity are deteriorated.

  The present invention has been made in view of the above-described conventional problems, and the object thereof is to install a shower plate on the surface of a shower head, suppress peeling of a product formed on the surface of the shower plate, and a substrate to be processed. An object of the present invention is to provide a vapor phase growth apparatus and a vapor phase growth method capable of ensuring the above film uniformity and film reproducibility.

  In order to solve the above problems, a vapor phase growth apparatus of the present invention includes a shower head provided with a plurality of gas discharge holes, a shower plate provided with a plurality of plate holes, and a substrate to be processed in a reaction furnace. The shower plate is disposed so as to cover the gas discharge surface side of the shower head, and a gas is introduced into the reaction chamber through the gas discharge hole and the plate hole to form a substrate to be processed. In the vapor phase growth apparatus for forming a film, a space is provided outside the region facing the substrate holding member of the shower plate and between the contact surfaces of the shower head and the shower plate, and the space of the shower plate is provided. A plurality of through-holes that communicate with the reaction chamber and introduce purge gas into the reaction chamber are provided in the region.

  Further, in order to solve the above problems, the vapor phase growth method of the present invention includes a shower head provided with a plurality of gas discharge holes, a shower plate provided with a plurality of plate holes, And a substrate holding member on which the processing substrate is placed, the shower plate is disposed so as to cover the gas discharge surface side of the shower head, and the substrate to be processed is introduced by introducing gas into the reaction chamber through the gas discharge hole and the plate hole. A vapor phase growth apparatus for forming a film on the outside of the region facing the substrate holding member of the shower plate and a space between the contact surface of the shower head and the shower plate, Purge gas is introduced through a plurality of through holes communicating with the reaction chamber provided in the region where the space is provided.

  In the shower head, the temperature of the outermost surface of the shower head is controlled by the refrigerant in order to suppress the adhesion of the product on the surface of the shower head, and the region through which the refrigerant flows extends over the entire surface of the shower head. This is because when only a part of the temperature is controlled, a temperature distribution is generated on the shower head surface and the shower head is distorted due to thermal expansion. When the shower plate is installed on the shower head surface as described above, the temperature of the substrate to be processed is heated by the heat from the substrate heater and the temperature rises, but the side surface exhaust flow outside the region facing the substrate holding member is increased. In the road, since the amount of heating from the substrate heater is small, the temperature rise is low, and the surface in contact with the shower head is cooled, so the temperature in the outer peripheral region of the shower plate is lower than that in the central portion. .

  In the shower plate having such a temperature distribution, the central high temperature region (heating region) facing the substrate holding member heated by the heat from the substrate heater is firmly adhered to the shower plate surface. Although a product is formed, a flake-like product that easily peels off is formed in a region (non-heated region) having a low temperature outside the region facing the substrate holding member.

  This is because in the non-heated area of the shower plate, there is no shower hole and it is impossible to eject the raw material gas, so the raw material gas stays on the surface of the shower plate, creating a stagnation region at the corner and the temperature is low. For this reason, because the product is not firmly fixed, the number of products that easily peel off in the form of flakes increases.

  However, according to the above invention, in the non-heated region of the shower plate, a space is disposed between the contact surfaces of the shower head and the shower plate, and the reaction chamber is formed in the region where the shower plate space is disposed. By providing a plurality of communicating through holes, the purge gas introduced outside the source gas channel in the reaction furnace can be introduced into the source gas channel through the through holes. As a result, gas can be ejected from the entire surface of the shower plate, and the source gas staying on the surface of the shower plate in the non-heated area of the shower plate is caused to flow toward the gas discharge port so that the stagnation area is less likely to occur at the corners. Thereby, the products formed on the surface of the shower plate can be reduced, and the formation of products that easily peel off in the form of flakes can be suppressed.

  In the vapor phase growth apparatus of the present invention, the space is preferably configured on the shower plate side.

  The space portion may be configured by processing the shower head side. For example, by applying a counterbore process to the shower hole area other than the shower hole area of the shower head surface, the surface of the shower plate may be in contact with an area where the shower hole of the shower head is installed, and a space part may be provided in the area subjected to the counterbore process. it can. However, since the flow path through which the coolant flows is formed on the shower head outermost surface side on the shower head side, applying a counterbore process other than the shower hole area on the shower head surface complicates the coolant flow path. Accompanied by. However, by applying processing to the shower plate side, for example, by applying counterbore processing to the shower plate area other than the shower hole area, the shower plate is in contact with the shower head surface and outside the shower hole area. The space portion can be formed by the counterbore processing portion. By processing the shower plate surface, it is possible to easily change the shape and distance of the space part. Compared to the processing of the shower head surface, the re-creation of the shower plate is cheaper and the shower plate can be easily replaced. Can be done. Therefore, it is easy to study the optimal shape and distance of the space that can reduce the products formed on the shower plate surface, and the film uniformity and film reproducibility on the substrate to be processed can be secured. A phase growth apparatus and a vapor phase growth method can be provided.

  In the vapor phase growth apparatus of the present invention, it is preferable to have a pressure regulating mechanism that varies the pressure in the space.

  If the pressure in the space is not set higher than the pressure in the reaction chamber, the source gas in the reaction chamber may flow back out of the reaction chamber through the through holes communicating with the plurality of reaction chambers provided in the shower plate. There is. Therefore, by arranging a pressure adjusting mechanism that varies the pressure in the space, the pressure in the space can be set higher than the pressure in the reaction chamber, preventing the above-described backflow and being arranged on the shower plate. The purge gas can be introduced into the source gas flow path through the through holes communicating with the plurality of reaction chambers. As a result, it is possible to reliably realize gas ejection from the entire surface of the through-hole, flow the source gas existing on the shower plate surface other than the shower hole region of the shower plate to the gas discharge port side, and further stagnation regions at the corners By making it hard to generate | occur | produce, it becomes possible to reduce the product formed in the shower plate surface.

  In the vapor phase growth apparatus of the present invention, it is preferable that a gas supply chamber is provided in the vicinity of the space.

  The purge gas introduced outside the source gas channel in the reaction chamber is introduced into the source gas channel through a plurality of through holes provided in the shower plate in the space region, so that it is close to the space. When the gas supply chamber is not provided, the flow rate of the purge gas introduced into the source gas flow path depends on the conductance determined by the space and the plurality of through holes. That is, it is difficult to adjust the flow rate of the purge gas introduced into the source gas flow path because the number of through holes and the hole diameter are changed. However, by providing a gas supply chamber capable of introducing gas in the vicinity of the space, it becomes possible to independently introduce the purge gas into the space. Thereby, it is easy to adjust the purge gas flow rate that can reduce the product formed on the surface of the shower plate without changing the shape of the space, film uniformity on the substrate to be processed and film reproducibility. It is possible to provide a vapor phase growth apparatus and a vapor phase growth method capable of ensuring the above.

  In the vapor phase growth apparatus of the present invention, it is preferable that the gas supply chamber has a gas supply chamber gas discharge hole for limiting a gas flow rate.

  If only a gas supply chamber capable of introducing gas is provided in the vicinity of the space, the purge gas may not be uniformly introduced into the space portion region but may be introduced with an uneven flow rate distribution. . The gas supply chamber has a shower-like gas supply chamber gas discharge hole that restricts the gas flow rate, so that the purge gas can be uniformly introduced from the gas supply chamber into the space region. The purge gas ejection can be made uniform. Therefore, it is possible to provide a vapor phase growth apparatus and a vapor phase growth method capable of reducing variations in products formed on the surface of a shower plate and ensuring film uniformity and film reproducibility on a substrate to be processed. be able to.

  As described above, the vapor phase growth apparatus of the present invention is a non-heated region portion of the shower plate, and a space is provided between the contact surfaces of the shower head and the shower plate, and the space is provided. A plurality of through holes communicating with the reaction chamber are formed in the partial shower plate. Further, a purge gas is introduced through the through hole.

  Thereby, the source gas existing on the surface of the shower plate in the non-heated region can be flowed to the gas discharge port side, and the stagnation region can be hardly generated at the corner. Therefore, it is possible to provide a vapor phase growth apparatus and a vapor phase growth method capable of reducing the products formed on the surface of the shower plate and ensuring film uniformity and reproducibility of the film on the substrate to be processed. Play.

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. FIG. 2 is a main part enlarged view showing a relation of a space part between a shower head and a shower plate in the vapor phase growth apparatus, and showing an A part region in FIG. 1 in an enlarged manner. It is a principal part enlarged view which shows the relationship of the space part of the shower head and shower plate in the conventional vapor phase growth apparatus, and expands and shows the same area | region as the A section of FIG. (A) is a photograph which shows the product adhesion situation to the conventional shower plate surface as a comparative example, (b) is a photograph which shows the product adhesion situation to the shower plate surface of this Embodiment. . (A), (b) shows the modification of the counterbore of the said shower plate, and is the principal part enlarged view which shows a shower plate. FIG. 4 is a main part enlarged view showing still another embodiment of the vapor phase growth apparatus according to the present invention and showing an enlarged region same as the part A in FIG. 1 showing a case where a counterbore is installed in the shower head. is there. It is sectional drawing which shows the structure of the conventional vertical shower head type vapor phase growth apparatus. It is sectional drawing which shows the structure of the conventional vertical type shower head type vapor phase growth apparatus. It is sectional drawing which shows the structure of the other conventional vapor phase growth apparatus. FIG. 9 shows still another embodiment of the vapor phase growth apparatus according to the present invention, and shows an enlarged main part showing the same region as part A of FIG. 1, showing a case where a gas supply chamber for introducing a purge gas is installed. FIG. FIG. 5 is a main part enlarged view showing another form of the gas supply chamber constituting member of the vapor phase growth apparatus according to the present invention and showing the same region as part A of FIG. 1 in an enlarged manner. FIG. 7 is a main part enlarged view showing still another embodiment of the gas supply chamber constituting member of the vapor phase growth apparatus according to the present invention and showing the same region as the part A of FIG. 1 in an enlarged manner. FIG. 3 is a schematic system diagram showing a purge gas introduction and pressure gauge system of the vapor phase growth apparatus according to the present invention. The other embodiment of the shower plate of the vapor phase growth apparatus in this invention is shown, Comprising: The principal part enlarged view which expands and shows the same area | region as the A section of FIG. 1 of the state which divided and comprised the shower plate It is. It is the schematic which shows the whole structure at the time of applying the vapor phase growth apparatus in this invention to a face down type | mold.

  An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. 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 a vertical showerhead type MOCVD apparatus 10 which is an example of a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus as a vapor phase growth apparatus of the present invention. .

  As shown in FIG. 1, the MOCVD apparatus 10 of the present embodiment has a reaction furnace 2 having a reaction chamber 1 as a growth chamber that is isolated from the atmosphere side and maintains an airtight state, and the inside of the reaction chamber 1. A substrate holding member 4 for mounting the substrate 3 to be processed, and a shower head 20 facing the substrate holding member 4 and having a shower plate 30 on the bottom surface. The reaction chamber 1 is separated into a reaction chamber 1 and an external reaction space 8 by a reaction chamber partition 7 provided inside the reaction furnace 2. A purge gas (N 2 gas or H 2 gas) is separated into the reaction external space 8 by a purge gas supply pipe 25. ) Has been introduced.

  The substrate holding member 4 is provided at one end of a rotation transmission member 5, and the rotation transmission member 5 can be rotated by a rotation mechanism (not shown). A substrate heater 6 is provided below the substrate holding member 4.

  When a thin film is formed on the main surface of the substrate 3 to be processed by the MOCVD apparatus 10, a source gas (hereinafter simply referred to as a gas) is passed from the shower head 20 through the gas discharge holes 31 a to the lower side of the shower head 20. It introduces into the reaction chamber 1 through the plate hole 31 of the provided shower plate 30. At this time, the substrate heating heater 6 heats the substrate 3 to be processed through the substrate holding member 4, and the film forming chemical reaction on the substrate 3 to be processed is promoted. A thin film is formed. The gas that has passed over the substrate 3 is discharged from the gas outlet 1a.

  Next, the detailed structures of the shower head 20 and the shower plate 30 which are characteristic structures of the present embodiment will be described.

  The shower head 20 includes a first gas distribution space 23 that is filled with a first gas, a second gas distribution space 24 that is filled with a second gas different from the first gas, and the first gas and the second gas. The refrigerant space 22 is filled with a refrigerant to be cooled. These spaces are stacked in the order of the refrigerant space 22, the first gas distribution space 23, and the second gas distribution space 24 from the substrate 3 to be processed. ing. A shower plate 30 is provided below the shower head 20, that is, on the substrate 3 to be processed.

  The second gas is introduced into the second gas distribution space 24 from the second gas introduction port 24a, and the second gas introduced into the second gas distribution space 24 includes the first gas distribution space 23 and the refrigerant space 22. Are introduced into the reaction chamber 1 through the plate holes 31 of the shower plate 30 that communicate with the gas discharge holes 31a of the second gas supply pipe 24b.

  In addition, the first gas is introduced into the first gas distribution space 23 from the first gas introduction port 23 a, and the first gas introduced into the first gas distribution space 23 has a plurality of second gas passing through the refrigerant space 22. The gas is introduced into the reaction chamber 1 through the plate hole 31 of the shower plate 30 that passes through the one gas supply pipe 23b and communicates with the gas discharge hole 31a of the first gas supply pipe 23b.

  Therefore, the first gas and the second gas are introduced into the reaction chamber 1 independently without being mixed in the shower head 20.

  As shown in FIG. 1, the shower head 20 is sealed by an O-ring 7a so as to maintain an airtight state with the reaction furnace 2, and the shower head 20 and the reaction furnace 2 are configured to be removable. . Further, an O-ring 7b is provided between the first gas distribution space 23 and the second gas distribution space 24, and an O-ring 7c is also provided between the second gas distribution space 24 and its top plate. Thus, each space can be separated and the airtight state of each space is maintained.

  Further, the shower plate 30 is fixed and installed in close contact with a screw or the like (not shown) on the shower head lower wall surface 20 a of the shower head 20.

  In the MOCVD apparatus 10 of the present embodiment, the substrate 3 is heated by the substrate heater 6 via the substrate holding member 4, and the film formation chemical reaction on the substrate 3 is promoted. A thin film is formed on the substrate 3 to be processed. Therefore, the temperature of the substrate holding member 4 itself is high, and the shower plate 30 on the opposite surface of the substrate holding member 4 is heated under the influence of the substrate heater 6 of the substrate holding member 4. That is, in the region of the shower plate 30 facing the substrate holding member 4 (hereinafter referred to as a heating region), the outer peripheral portion region (hereinafter referred to as “heating region”) is heated by the substrate holding member 4 and outside the region of the substrate holding member 4 facing. In the non-heated region), the heating from the substrate holding member 4 is difficult to reach. The shower head 20 has a refrigerant space 22, and the shower head lower wall surface 20 a of the shower head 20 is cooled by the refrigerant space 22 so that the temperature is controlled to be uniform.

  FIG. 3 is an enlarged view showing the same region as the portion A in FIG. 1 when a conventional shower plate is installed.

  Since the temperature of the shower head lower wall surface 20a is kept uniform, the temperature of the shower plate wall surface 30a on the substrate 3 side of the shower plate 30 is determined by heating from the substrate holding member 4. Therefore, the temperature of the shower plate wall surface 30a is higher in the heating region in FIG. 3 and lower in the non-heating region than in the heating region. FIG. 4A is a partially enlarged photograph of the shower plate wall surface 30a after film formation when a conventional shower plate is installed. As can be seen from FIG. 4A, in the heating region, no film peeling or the like is observed in the product 44, and a beautiful thin film is generated. However, it can be seen that in the product 44 in the non-heated region, miscellaneous crystals in which film peeling (hereinafter referred to as peeling product 45) is observed are generated. That is, since the shower plate 30a wall surface temperature is lower in the non-heated region than in the heated region, a peel product 45 as shown in FIG. 4A is generated.

  On the other hand, in the present embodiment, a space portion 41 is formed between the shower head lower wall surface 20a of the shower head 20 and the shower plate 30 in the non-heated region.

  This configuration will be described with reference to FIG. FIG. 2 is an enlarged view showing a region A in FIG.

  As shown in FIG. 2, the shower plate 30 is provided with a counterbore 42 on the surface of the shower plate 30 on the side in contact with the shower head lower wall surface 20a so as to cover the exhaust passage 9 in the non-heated region. A space 41 is formed between the shower head lower wall surface 20 a and the shower plate 30. Furthermore, a plurality of through holes 43 communicating with the reaction chamber are formed in the region where the space of the shower plate 30 is disposed. The reaction chamber 1 is separated from the reaction external space 8 by the reaction chamber partition wall 7, and purge gas (N 2 gas or H 2 gas) is introduced into the reaction external space 8 by the purge gas supply pipe 25.

  Further, the pressure in the reaction chamber 1 and the space 41 is adjusted by the pressure adjusting mechanism 13 so that the reaction chamber 1 side is lowered. This is because, when the pressure in the space portion 41 is not set higher than the pressure in the reaction chamber 1, the reaction chamber 1 passes through the plurality of through holes 43 communicating with the inside of the reaction chamber 1 disposed in the shower plate 30. There is a possibility that the inside source gas flows backward to the outside of the reaction chamber 1. Therefore, the pressure adjusting mechanism 13 that varies the pressure in the space 41 is disposed, and the pressure in the space 41 is set higher than the pressure in the reaction chamber 1, thereby preventing the above-described backflow and the shower plate 30. The purge gas can be reliably ejected into the reaction chamber 1 through the plurality of through holes 43 provided. As shown in FIG. 13, the pressure regulating mechanism 13 is configured such that a reaction chamber pressure gauge 11 is installed in the exhaust pipe 16, a reaction external space pressure gauge 12 is installed on the wall of the reaction furnace 2, and a purge gas introduction pipe In 25, a pressure adjusting mechanism 13 and a mass flow controller 14 are installed. The pressure P2 of the reaction external space pressure gauge 12 is set to be higher than the pressure P1 of the reaction chamber pressure gauge 11, and the pressure adjusting mechanism 13 uses a pressure control valve or the like to adjust the pressure of the reaction furnace external space pressure gauge 12. It is adjusted to be P2.

  FIG. 4B is a partially enlarged photograph of the shower plate wall surface 30a after film formation when the space portion of the present embodiment is installed. As can be seen from FIG. 4 (b), no film peeling or the like is observed in the product 44 regardless of the heating region and the non-heating region, and a beautiful thin film is generated. Therefore, according to the present embodiment, it is possible to suppress peeling of a product formed on the surface of the shower plate 30 and to ensure film uniformity and film reproducibility on the substrate 3 to be processed.

  According to the above configuration, the source gas existing on the surface of the shower plate 30 in the non-heated region can be made to flow toward the gas discharge port 1a, and the stagnation region is less likely to be generated at the corners. It is possible to reduce the product 44 formed on the surface of the substrate. Furthermore, since the product 44 generated on the surface of the shower plate 30 is thickened by repeating the film formation, the possibility of peeling increases in proportion to the number of film formations. Since the amount of the product 44 at the time of film formation decreases, the number of film formations until peeling can be increased. Therefore, peeling of the product formed on the surface of the shower plate 30 can be suppressed and film uniformity and film reproducibility on the substrate to be processed 3 can be ensured.

  The shape of the counterbore 42 provided on the shower plate 30 may be a shape as shown in FIGS. 5 (a) and 5 (b).

  On the other hand, FIG. 6 is an enlarged view showing another embodiment of the same region as the portion A in FIG.

  By providing counterbore 42 on the shower head 20 in the non-heating region, a space 41 is formed between the shower head lower wall surface 20 a and the shower plate 30. Further, a through-hole 43 communicating with the plurality of reaction chambers is formed in the shower plate 30 in the space 41 region.

  Even in the above configuration, in the non-heated region, there is a space 41 between the shower head lower wall surface 20a and the shower plate 30, and the shower plate 30 in the space 41 region communicates with a plurality of reaction chambers. Since the holes 43 are configured, it is possible to suppress peeling of the product 44 formed on the surface of the shower plate 30 and to ensure film uniformity and film reproducibility on the substrate 3 to be processed.

  Next, FIG. 10 shows another embodiment of the purge gas introduction unit. Until now, the purge gas has been introduced into the reaction external space 8 separated from the reaction chamber 1 by the reaction chamber partition wall 7, but in this example, the purge gas toward the gas outlet 1 a and the purge gas toward the space 41 are used. Since the flow rate of the purge gas introduced into the reaction chamber 1 through the through hole 43 is determined by the balance of conductance between the two, the flow rate of the purge gas introduced into the reaction chamber 1 is controlled. Difficult to do. Therefore, the gas supply chamber constituting member 48 is installed in the vicinity of the space portion 41 in the reaction external space 8 to constitute the gas supply chamber 46. The purge gas supply pipe 25 includes at least two systems for introducing purge gas into the reaction external space 8 and introducing purge gas into the gas supply chamber 46.

  With the above configuration, purge gas whose flow rate has been adjusted can be introduced into the gas supply chamber 46, so that it is determined through the through hole 43 without being affected by the film formation conditions (growth pressure, raw material gas flow rate, etc.). It becomes possible to introduce a purge gas at a flow rate into the reaction chamber 1. This facilitates the adjustment of the purge gas flow rate that can reduce the product 44 formed on the surface of the shower plate without changing the shape of the space portion 41, and makes it possible to adjust the film uniformity and film on the substrate 3 to be processed. It is possible to provide a vapor phase growth apparatus and a vapor phase growth method capable of ensuring the reproducibility of the above.

  Furthermore, another form of the gas supply chamber constituting member 48 is shown in FIG. The gas supply chamber constituting member 48 is provided with a shower-like gas supply chamber gas discharge hole 47 for limiting the gas flow rate between the space 41 and the gas supply chamber 46. If only the gas supply chamber 46 capable of introducing gas is provided in the vicinity of the space portion 41, the purge gas is not uniformly introduced into the space portion 41 region, but may be introduced with an uneven flow rate distribution. There is. This is because the purge gas supply pipe 25 for introducing the purge gas into the gas supply chamber 46 is introduced by one or a plurality of circular pipes, but the gas supply chamber 46 has a donut shape. This is because the flow velocity on the side close to the supply pipe 25 is increased, and the flow distribution is shifted in the gas supply chamber 46. However, as described above, by providing the gas supply chamber 46 with the shower-like gas supply chamber gas discharge hole 47 that restricts the gas flow rate, the flow distribution from the gas supply chamber 46 to the space portion 41 is offset. Can be small. Accordingly, the purge gas can be uniformly introduced from the gas supply chamber 46 into the space 41 region, and the purge gas ejection from the plurality of through holes 43 can be made uniform. Further, the gas supply chamber gas discharge hole 47 may be installed on the wall surface of the reactor 2 as shown in FIG.

  According to the above configuration, the vapor phase growth apparatus and the vapor phase growth that can reduce the variation of the product 44 formed on the surface of the shower plate and can ensure the film uniformity and the film reproducibility on the substrate to be processed. A method can be provided.

  The shower plate 30 does not need to be an integral part, and can be configured by being divided into a shower plate body 33a and a shower plate peripheral member 33b as shown in FIG. In this case, the shower plate main body 33a is held so as to be in contact with the shower head lower wall surface 20a, and the shower plate peripheral member 33b is held with the shower head lower wall surface 20a and the space 41. The shower plate main body 33a and the shower plate peripheral member 33b are fixed and installed in close contact with screws or the like (not shown) on the shower head lower wall surface 20a of the shower head 20.

  In the present invention, it goes without saying that the shapes of the reactor, shower plate and other members constituting the MOCVD apparatus are not limited to the shapes shown in FIG.

  Further, as shown in FIG. 15, a reaction furnace 2 having a reaction chamber 1 that isolates the inside from the atmosphere side and maintains an airtight state, and a substrate that is provided inside the reaction chamber 1 and on which a substrate 3 to be processed is placed. A face-down type vapor phase growth in which a holding member 4 and a shower head 20 facing the substrate holding member 4 and having a shower plate 30 on the upper surface are provided, and a reactive gas is introduced into the substrate 3 to be processed from below. The present invention can also be applied to the MOCVD apparatus 10 as an apparatus.

  Furthermore, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. 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.

  The present invention is a vapor phase growth method such as a vertical MOCVD apparatus using a shower plate that introduces a gas from a peripheral portion into a space above the shower plate and introduces a reactive gas to a substrate surface from a plurality of gas discharge holes of the shower plate. It can be used for an apparatus and a vapor phase growth method.

1 Reaction chamber (growth chamber)
1a Gas outlet 2 Reaction furnace 3 Substrate 4 Substrate holding member 5 Rotation transmission member 6 Substrate heater 7 Reaction chamber partition 8 Reaction external space 9 Exhaust flow path 10 MOCVD apparatus (vapor phase growth apparatus)
DESCRIPTION OF SYMBOLS 11 Reaction chamber pressure gauge 12 Reaction external space pressure gauge 13 Pressure regulation mechanism 14 Mass flow controller 16 Exhaust piping 20 Shower head 20a Shower head lower wall surface 22 Refrigerant space 23 First gas distribution space 23a First gas introduction port 23b First gas supply pipe 24 second gas distribution space 24a second gas inlet 24b second gas supply pipe 25 purge gas supply pipe 30 shower plate 30a shower plate wall surface 31 plate hole 31a gas discharge hole 33a shower plate body 33b shower plate peripheral member 41 space portion counterbore 43 Through-hole 44 Product 45 Peeling product 46 Gas supply chamber 47 Gas supply chamber Gas discharge hole 48 Gas supply chamber component

Claims (6)

In the reaction furnace, a shower head provided with a plurality of gas discharge holes,
A shower plate provided with a plurality of plate holes;
A substrate holding member on which a substrate to be processed is placed,
The shower plate is disposed so as to cover the gas discharge surface side of the shower head,
In the vapor phase growth apparatus for introducing a gas into the reaction chamber through the gas discharge hole and the plate hole and forming a film on the substrate to be processed,
Outside the region of the shower plate facing the substrate holding member,
And a space is arranged between the contact surfaces of the shower head and the shower plate,
A vapor phase growth apparatus characterized in that a plurality of through holes that communicate with the reaction chamber and introduce purge gas into the reaction chamber are provided in a region where the space of the shower plate is disposed.   The vapor phase growth apparatus according to claim 1, wherein the space is configured on the shower plate side.   The vapor phase growth apparatus according to claim 1, further comprising a pressure adjusting mechanism that varies a pressure in the space.   The vapor phase growth apparatus according to any one of claims 1 to 3, wherein a gas supply chamber is disposed in the vicinity of the space.   5. The vapor phase growth apparatus according to claim 4, wherein the gas supply chamber has a gas supply chamber gas discharge hole for limiting a gas flow rate. In the reaction furnace, a shower head provided with a plurality of gas discharge holes,
A shower plate provided with a plurality of plate holes;
A substrate holding member on which a substrate to be processed is placed,
The shower plate is disposed so as to cover the gas discharge surface side of the shower head,
A vapor phase growth apparatus for introducing a gas into a reaction chamber through the gas discharge hole and the plate hole to form a film on the substrate to be processed;
Outside the region of the shower plate facing the substrate holding member,
And, a space is disposed between the contact surfaces of the shower head and the shower plate,
A vapor phase growth method, wherein a purge gas is introduced through a plurality of through holes communicating with the inside of a reaction furnace provided in a region where the space of the shower plate is provided.