JP2010100925A - Vapor deposition apparatus and vapor deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition apparatus and a vapor deposition method by which the gas concentration distribution on the surface of a substrate to be treated in a growth chamber can be uniformized and the thickness of a deposition film and the compositional ratio can be improved when a raw material gas is introduced from a peripheral part of a shower head. <P>SOLUTION: A shower head 20 includes: an outer annular flow passage 23a for a group-III gas and an outer annular flow passage 24a for a group-V gas to each of which a raw material gas is introduced; a buffer area 23b for the group-III gas and a buffer area 24b for the group-V gas of the raw material gas, which are located in the inner side of partitions 23d, 24d with openings; and a shower plate 21 having a plurality of discharge holes H3 for the group-III gas and a plurality of discharge holes H5 for the group V gas. In the gas buffer area 23b for the group III gas, partition walls 40 for partitioning the peripheral part of the gas buffer area 23b for the group III gas into a plurality of layers of the stacking direction are provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

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, and more particularly to a method of supplying a source gas in the vapor phase growth apparatus. .

In the manufacture of light-emitting diodes and semiconductor lasers, organometallic gases such as trimethylgallium (TMG) or trimethylaluminum (TMA) and hydrogen compound gases such as ammonia (NH ₃ ), phosphine (PH ₃ ) or arsine (AsH ₃ ) MOCVD (Metal Organic Chemical Vapor Deposition), in which a compound semiconductor crystal is grown on a substrate, is introduced as a source gas contributing to film formation into a growth chamber.

  MOCVD is a method in which a compound semiconductor crystal is grown on a substrate by introducing the raw material gas together with an inert gas such as hydrogen or nitrogen into the growth chamber and heating it to cause a gas phase reaction on a predetermined substrate. It is. In manufacturing a compound semiconductor crystal using the MOCVD method, it is simultaneously required to improve the quality of the compound semiconductor crystal to be grown, to reduce the cost, to increase the yield, and to increase the production capacity.

  FIG. 22 shows a schematic configuration of an example of a vertical shower head type MOCVD apparatus which is a conventional vapor phase growth apparatus used for MOCVD.

  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.

  In the case of forming a thin film by supplying a plurality of reaction gases and reacting them on the substrate 107, conventionally, a plurality of gases are mixed in a shower head and a large number of gas discharges provided on the shower plate 110 are mixed. A method of blowing a reactive gas from the outlet to the substrate 107 has been adopted.

  By the way, in order to keep the quality of the compound semiconductor crystal grown on the substrate constant, it is necessary to grow a thin film having a uniform film thickness distribution on the substrate. For this reason, it is essential to supply the reaction gas and the inert gas introduced into the growth chamber with a uniform concentration distribution.

  In order to solve this problem, for example, Patent Document 1 discloses a method in which a reaction gas is supplied onto a substrate with a uniform concentration distribution and a gas phase reaction is performed on the substrate. Specifically, as shown in FIG. 23, a gas introduction port 202 is provided in the central portion above the installed substrate 201, and an outer wall that expands from the gas introduction port 202 to the shower plate 203 is provided. The difference in reaction gas velocity at the gas discharge holes of the plate 203 can be relaxed, and the concentration distribution of the reaction gas on the substrate 201 is made uniform.

  Further, in Patent Document 2, as shown in FIG. 24, the substrate has a plurality of gas introduction portions 301... And a flow rate is controlled by a flow rate adjustment portion 302 provided in each gas introduction portion 301. The reaction gas can be uniformly supplied to the surface 303.

  Furthermore, in Patent Document 3, as shown in FIG. 25, reaction gas is introduced into the growth chamber 401 through the shower plate 404 from the gas introduction hole 403 disposed in the annular gas flow path 402 disposed in the upper peripheral portion of the growth chamber 401. In addition to discharging, an annular gas discharge unit 405 is installed around the growth chamber 401, and exhaust gas is discharged through the exhaust holes 406 evenly arranged in the gas discharge unit 405, so that the reaction gas is supplied to the surface of the substrate 407. Uniform supply is possible.

  On the other hand, since the growth chamber in which film formation is performed is often used under reduced pressure, the pressure in the shower head is much higher than in the growth chamber, and it is inevitable that a gas phase reaction occurs in the shower head. It was. When a gas phase reaction occurs in the shower head, the reaction product closes the gas discharge hole of the shower head, and the reaction gas cannot be supplied into the growth chamber.

  In order to solve this problem, for example, in Patent Document 4, as shown in FIG. 26, intermediate chambers 501 and 502 are provided for each of two types of supply gas, and the reaction gas is supplied from the intermediate chambers 501 and 502 to a shower plate 503. A method is disclosed in which two types of gas are supplied to the growth chamber 504 in a separated state by passing the gas discharge holes 501a and 502a. Thereby, since the reaction gas is supplied in a separated state, a gas phase reaction does not occur in the shower head 505. Such a configuration is also disclosed in Patent Documents 5 and 6, for example.

JP 2005-72196 A (published March 17, 2005) JP 2000-294538 A (released on October 20, 2000) Japanese Patent Laid-Open No. 3-203227 (published on September 4, 1991) JP-A-8-91989 (published on April 9, 1996) Japanese Patent Laid-Open No. 5-152208 (released on June 18, 1993) JP 2000-144432 A (published May 26, 2000)

  However, the conventional vapor phase growth apparatuses disclosed in Patent Documents 4 to 6 have a problem that it is difficult to uniformly supply the reaction gas or the inert gas.

  More specifically, in Patent Document 6, for example, as shown in FIG. 27, the upper gas space 601 can be uniformly supplied with a reactive gas or an inert gas by the method disclosed in Patent Documents 1 and 2, for example. Although possible, it is difficult to uniformly supply the reaction gas or the inert gas to the middle gas space 602 shown in FIG. 27 by the methods disclosed in Patent Documents 1 and 2.

  Further, as described above, in manufacturing a compound semiconductor crystal, it is required to suppress the cost, increase the yield, and increase the production capacity at the same time, so that the MOCVD apparatus needs to be enlarged. Along with the increase in size of such an apparatus, it is a big problem to supply the reaction gas or the inert gas uniformly.

  In this regard, in Patent Documents 4 to 6, there is a description that uniform film growth is possible over a large area, but no specific means for uniformly supplying the reaction gas is described.

  For example, as a result of calculation for confirming the uniformity of the reaction gas in the middle gas space 602 shown in FIG. 27 using the configuration in Patent Document 3 shown in FIG. 25, as shown in FIG. However, the problem is that the reaction gas is not supplied uniformly, because the reaction gas is not supplied uniformly.

  The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to make uniform the gas concentration distribution on the surface of the substrate to be processed in the growth chamber when the source gas is introduced from the peripheral portion of the shower head. An object of the present invention is to provide a vapor phase growth apparatus and a vapor phase growth method that can improve the film thickness and composition ratio.

  In order to solve the above problems, the vapor phase growth apparatus of the present invention supplies a raw material gas into a growth chamber from a gas supply means provided opposite to the growth chamber into a growth chamber and applies it to a substrate to be processed in the growth chamber. In the vapor phase growth apparatus for performing vapor phase growth, the gas supply means is provided in an annular shape on the outer periphery, the outer ring channel into which the source gas is introduced, the inner ring channel, and the source gas. An inner wall with an opening having an opening therethrough, an intermediate chamber of a source gas located inside the inner wall with the opening, and a shower plate having a plurality of gas discharge holes located downstream of the intermediate chamber In addition, the intermediate chamber is provided with a partition wall that partitions the peripheral portion of the intermediate chamber into a plurality of layers in the stacking direction.

  In order to solve the above-described problem, the vapor phase growth method of the present invention supplies a source gas into the growth chamber in a shower form from a gas supply means provided facing the growth chamber, and applies it to the substrate to be processed in the growth chamber. In the vapor phase growth method for performing vapor phase growth, the raw material gas is introduced into the outer ring channel of the gas supply means provided in an annular shape on the outer periphery, and the opening of the inner wall with the opening provided inside the outer ring channel Through the intermediate gas chamber located inside the inner wall with the opening, through a portion partitioned by a plurality of layers in the stacking direction at the periphery of the intermediate chamber, and the intermediate chamber The source gas is supplied into the growth chamber in a shower form from a plurality of gas discharge holes of the shower plate located on the downstream side, and vapor phase growth is performed.

  According to the invention described above, the gas supply means has an outer ring channel that is annularly provided on the outer periphery and into which the source gas is introduced, and an opening that is provided inside the outer ring channel and through which the source gas passes. An inner wall with an opening, a source gas intermediate chamber located inside the inner wall with an opening, and a shower plate having a plurality of gas discharge holes located downstream of the intermediate chamber.

  For this reason, by passing the source gas from the outer ring channel to the intermediate chamber, the space above the shower plate can be effectively utilized, and the entire vapor phase growth apparatus can be thinned.

  By the way, when the source gas is passed from the outer ring flow path to the intermediate chamber, the gas flow velocity in the peripheral portion of the intermediate chamber is large, and the gas flow velocity decreases as it goes deeper into the central portion of the intermediate chamber. As a result, the source gas discharged into the growth chamber from the plurality of gas discharge holes of the shower plate has a high gas flow rate at the periphery of the shower plate, and the gas flow rate decreases as it goes deeper into the center of the shower plate. As a result, the source gas is not uniformly supplied to the substrate to be processed in the growth chamber.

  Therefore, in the present invention, the intermediate chamber is provided with a partition that partitions the peripheral portion of the intermediate chamber into a plurality of layers in the stacking direction. That is, one or a plurality of partition walls are provided in parallel to the shower plate in the peripheral portion on the outer peripheral side of the central portion of the intermediate chamber.

  For this reason, the raw material gas passing through the counter-shower plate side of the partition wall in the peripheral part of the intermediate chamber enters the central part of the intermediate chamber and is then discharged from the plurality of gas discharge holes in the central part of the shower plate to the growth chamber. . On the other hand, the source gas that passes through the shower plate side of the partition wall in the peripheral portion of the intermediate chamber is discharged into the growth chamber from the plurality of gas discharge holes in the peripheral portion of the shower plate in the peripheral portion of the intermediate chamber.

  As a result, the source gas is discharged from the plurality of gas discharge holes into the growth chamber in a balanced manner from both the peripheral portion and the central portion of the shower plate.

  Therefore, when the source gas is introduced from the peripheral portion of the shower head, the gas concentration distribution on the substrate surface to be processed in the growth chamber can be made uniform, and the film thickness and composition ratio can be improved. A growth apparatus and a vapor deposition method can be provided.

  In the vapor phase growth apparatus of the present invention, the partition wall is composed of two or more partitioning the peripheral portion of the intermediate chamber into three or more layers, and the partition wall farther from the shower plate extends to the center of the intermediate chamber. Is possible.

  As a result, the partition wall is composed of two or more partitions that divide the peripheral portion of the intermediate chamber into three or more layers, so that the partition wall is divided into three or more layers from the outer ring passage. Here, in this invention, the partition farther from the shower plate extends to the center of the intermediate chamber. For this reason, the source gas flowing through the layer farther from the shower plate goes deeper into the center of the intermediate chamber, and the depth is divided according to the number of partition walls. As a result, the source gas can be discharged from the plurality of gas discharge holes into the growth chamber in a more balanced manner from the periphery to the center of the shower plate. This configuration is advantageous for increasing the size of the vapor phase growth apparatus.

  In the vapor phase growth apparatus of the present invention, it is possible that a through hole is formed in the partition wall.

  Thus, it is possible to appropriately finely adjust the gas concentration distribution on the surface of the substrate to be processed in the growth chamber so as to avoid a sudden merging of the source gases on the free end side of the partition wall.

  Further, for example, when the intermediate chamber is divided into a plurality of layers using a plurality of source gases, the partition wall can be passed through a through pipe penetrating the lower layer, and the assembly and replacement of the partition wall are facilitated, and the shower head The intermediate chamber can have a simple structure, and a vapor phase growth apparatus can be manufactured at low cost.

  In the vapor phase growth apparatus of the present invention, the opening area per unit area of the through hole in the partition wall is preferably larger toward the center than the peripheral portion of the intermediate chamber.

  That is, when there is no through hole in the partition, the source gas passing through the partition opposite the shower plate and the source gas passing through the partition shower plate are merged at the free end side of the partition, that is, in the center of the intermediate chamber. The increase in the flow velocity of the part that changes is abrupt, and turbulence may occur.

  In this regard, in the present invention, the opening area per unit area of the through hole in the partition wall is larger toward the center than the peripheral part of the intermediate chamber, so that the source gas passing through the partition wall on the side opposite to the shower plate is intermediate As the source gas moves toward the center of the chamber, it gradually flows into the source gas passing through the shower plate side of the partition wall.

  As a result, at the free end of the partition wall, it is possible to mitigate the rapid increase in flow velocity and the occurrence of turbulence in the portion where the source gas passing through the partition opposite the shower plate side and the source gas passing through the partition wall shower plate side merge. it can.

  Therefore, the gas concentration distribution on the surface of the substrate to be processed in the growth chamber can be made uniform, and the film thickness and composition ratio can be improved.

  In the vapor phase growth apparatus of the present invention, the partition may be provided so as to be inclined away from the shower plate toward the center of the intermediate chamber.

  Thereby, as the source gas flowing through the layer moving away from the shower plate goes into the middle part of the intermediate chamber, the flow velocity increases, and it becomes easier to go into the middle part of the intermediate chamber.

  Therefore, when the source gas is introduced from the peripheral portion of the shower head, the gas concentration distribution on the surface of the substrate to be processed in the growth chamber can be made uniform, and the film thickness and composition ratio can be improved.

  In the vapor phase growth apparatus of the present invention, the partition may be provided at a position crossing the opening provided on the inner wall with the opening. That is, when the source gas flows into the intermediate chamber through the opening of the inner wall with the opening from the outer ring flow path, the opening is adjacent to the adjacent layer in the stacking direction in the peripheral portion of the intermediate chamber, and is common. An opening is shared by adjacent layers in the stacking direction.

  As a result, a plurality of flow rate adjusting parts for adjusting the flow rate of the source gas flowing through each layer in the stacking direction in the peripheral part of the intermediate chamber are shared with one, and the flow rate adjusting valves can be reduced. . As a result, a simple structure can be obtained, and it can be manufactured at a low cost.

  In the vapor phase growth apparatus according to the present invention, the partition may be provided in non-contact with the inner wall with the opening.

  Thereby, in a non-contact area | region, a flow path resistance can be made small because there is no partition. As a result, the flow velocity of the raw material gas in this non-contact region increases, and the raw material gas can be easily penetrated into the central portion of the intermediate chamber.

  In this configuration as well, a plurality of flow rate adjustment units are shared by one, and the number of flow rate adjustment valves can be reduced. Moreover, the area of a partition can be reduced and the material cost of a partition can be reduced.

  In the vapor phase growth apparatus of the present invention, the partition wall may have a bent portion bent or curved on the shower plate side at the center side end portion of the intermediate chamber.

  Thereby, the source gas flowing through the layer on the shower plate side in the peripheral part of the intermediate part can be forcibly directed to the shower plate side. For this reason, it is only necessary to consider the flow rate when discharging from the gas discharge hole to the growth chamber in each planar region of each partition wall, so that the control of the flow rate of the source gas is facilitated.

  In the vapor phase growth apparatus according to the present invention, the bent portion of the partition wall may be in contact with the surface of the intermediate chamber on the shower plate side or the shower plate.

  This makes it easy to control the flow rate of the source gas because the flow rate at the time of discharge from the gas discharge hole in each planar region of each partition wall to the growth chamber is taken into consideration.

  In the vapor phase growth apparatus according to the present invention, the intermediate chamber is composed of a plurality of stacked individual intermediate chambers that are separated by a separation plate and accommodate different kinds of source gases, respectively, and the stacked stacked individual chambers. The individual intermediate chamber on the shower plate side in the intermediate chamber is connected to a plurality of gas discharge holes for supplying different types of source gases in the shower plate, and is on the side opposite to the shower plate than the individual intermediate chamber on the shower plate side. It can be assumed that an individual gas supply pipe communicating with the individual intermediate chamber is provided through.

  That is, in the present invention, the intermediate chamber is composed of a plurality of stacked individual intermediate chambers, and the individual intermediate chamber on the shower plate side in the individual intermediate chamber is located on the side opposite to the shower plate than the individual intermediate chamber on the shower plate side. An individual gas supply pipe communicating with the individual intermediate chamber is provided therethrough.

  As described above, when the individual gas supply pipes are provided in the individual intermediate chamber in a forested manner, when the raw material gas is passed from the outer ring channel to the individual intermediate chamber, the gas flow velocity in the peripheral portion of the individual intermediate chamber is large, The gas flow velocity becomes particularly small due to the resistance of the individual gas supply pipes that stand in the center of the chamber.

  In this respect, in the present invention, since the partition wall that partitions the peripheral portion of the individual intermediate chamber in the intermediate chamber into a plurality of layers in the stacking direction is provided, the source gas is balanced from both the peripheral portion and the central portion of the shower plate. A plurality of gas discharge holes are discharged into the growth chamber.

  Therefore, when the source gas is introduced from the peripheral portion of the shower head, the gas concentration distribution on the substrate surface to be processed in the growth chamber can be made uniform, and the film thickness and composition ratio can be improved. A growth apparatus can be provided.

  In the vapor phase growth apparatus according to the present invention, a cooling means may be provided between the shower plate and the intermediate chamber.

  Thereby, when introduced from the peripheral part of the shower head, the source gas can be cooled by the cooling means, and the gas concentration distribution on the surface of the substrate to be processed in the growth chamber can be made uniform, and the film thickness and composition can be increased. A vapor phase growth apparatus that can improve the ratio can be provided.

  As described above, in the vapor phase growth apparatus of the present invention, the gas supply means is provided in an annular shape on the outer periphery, the outer ring channel into which the source gas is introduced, the inner side of the outer ring channel, and the above An inner wall with an opening having an opening through which the source gas passes, an intermediate chamber of the source gas located inside the inner wall with the opening, and a shower plate having a plurality of gas discharge holes located on the downstream side of the intermediate chamber The intermediate chamber is provided with a partition that partitions the peripheral portion of the intermediate chamber into a plurality of layers in the stacking direction.

  As described above, the vapor phase growth method of the present invention introduces the source gas into the outer ring channel of the gas supply means provided in a ring shape on the outer periphery, and has an inner side with an opening provided inside the outer ring channel. Passing the source gas from the opening of the wall to the intermediate chamber of the source gas located inside the inner wall with the opening, through a portion partitioned by a partition wall in a stacking direction at the periphery of the intermediate chamber, In this method, the source gas is supplied in a shower form from a plurality of gas discharge holes of the shower plate located on the downstream side of the intermediate chamber into the growth chamber to perform vapor phase growth.

  Therefore, when the source gas is introduced from the periphery of the shower head, the gas concentration distribution on the surface of the substrate to be processed in the growth chamber can be made uniform, and the film thickness and composition ratio can be improved. There is an effect that a phase growth apparatus and a vapor phase growth method can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of a vapor phase growth apparatus according to the present invention, and is a cross-sectional view illustrating a right half configuration of a shower head of the vapor phase growth apparatus. It is the schematic which shows the whole structure of the said vapor phase growth apparatus. It is sectional drawing which shows the structure of the shower head of the said vapor phase growth apparatus. (A) is a top view which shows the structure of the shower plate in the said shower head, (b) is a top view which shows the other structure of the shower plate in the said shower head. It is a perspective view which shows the structure of the V group type outer ring flow path of the V group type gas supply part in the said shower head. It is a graph which shows the relationship between the distance from the reaction furnace center in the shower head shown in FIG. 1, and the flow velocity. It is a sectional view showing the modification of the above-mentioned vapor phase growth apparatus, and showing the composition of the right half in the shower head. It is a schematic diagram which shows the other modification of the said vapor phase growth apparatus, and shows the structure of the right half in a shower head. It is sectional drawing which shows the further another modification of the said vapor phase growth apparatus, Comprising: It is a right side half structure in a shower head. It is a graph which shows the relationship between the distance from the reactor center in the shower head shown in FIG. 9, and the flow velocity. It is a schematic diagram which shows the other modification of the said vapor phase growth apparatus, Comprising: It is a schematic diagram which shows the structure of the right half in a shower head. It is sectional drawing which shows the further another modification of the said vapor phase growth apparatus, Comprising: It is a right side half structure in a shower head. It is sectional drawing which shows the further another modification of the said vapor phase growth apparatus, Comprising: It is a right side half structure in a shower head. It is a graph which shows the relationship between the distance from the reaction furnace center in the shower head shown in FIG. 13, and the flow velocity. It is sectional drawing which shows the structure of the comparative example in the shower head of the said vapor phase growth apparatus. It is sectional drawing which shows the structure of the right half in the shower head of the comparative example shown in FIG. It is a graph which shows the relationship between the distance from the reactor center in the shower head of the comparative example shown in FIG. 15, and the flow velocity. FIG. 9 is a cross-sectional view showing another embodiment of the vapor phase growth apparatus according to the present invention and showing the right half of the shower head. It is a sectional view showing other modification of the above-mentioned vapor phase growth apparatus, and showing the composition of the right half in a shower head. It is sectional drawing which shows the further another modification of the said vapor phase growth apparatus, Comprising: It is a right side half structure in a shower head. It is sectional drawing which shows the further another modification of the said vapor phase growth apparatus, Comprising: It is a right side half structure in a shower head. 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 other conventional vertical shower head type vapor phase growth apparatus. It is sectional drawing which shows the structure of the other conventional vertical shower head type vapor phase growth apparatus. It is sectional drawing which shows the structure of the other conventional vertical shower head type vapor phase growth apparatus. It is sectional drawing which shows the structure of the other conventional vertical shower head type vapor phase growth apparatus. It is sectional drawing which shows the structure of the other conventional vertical shower head type vapor phase growth apparatus.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS.

  FIG. 2 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 embodiment. Indicates.

  As shown in FIG. 2, the MOCVD apparatus 10 of the present embodiment includes a reaction furnace 2 having a growth chamber 1 that is a hollow portion, a susceptor 4 on which a substrate 3 to be processed is placed, and the susceptor 4. A shower head 20 as a gas supply means having a shower plate 21 on the bottom surface is included.

  A heater 5 and a support base 6 for heating the substrate 3 to be processed are provided below the susceptor 4, and a rotating shaft 7 attached to the support base 6 is rotated by an actuator or the like (not shown), thereby the susceptor 4. The heater 5 rotates while maintaining the state in which the upper surface of the susceptor 4 (the surface on the shower plate 21 side) is parallel to the opposing shower plate 21. A cover plate 8 serving as a heater cover is provided around the susceptor 4, the heater 5, the support base 6 and the rotary shaft 7 so as to surround the susceptor 4, the heater 5, the support base 6 and the rotary shaft 7. .

  Further, the MOCVD apparatus 10 includes a gas discharge unit 11 for discharging the gas inside the growth chamber 1 to the outside through the peripheral gas discharge port 1a, a purge line 12 connected to the gas discharge unit 11, and the purge And an exhaust gas treatment device 13 connected to the line 12. Thereby, the gas introduced into the inside of the growth chamber 1 is discharged to the outside of the growth chamber 1 through the gas discharge unit 11, and the discharged gas is introduced into the exhaust gas treatment device 13 through the purge line 12. 13 is detoxified.

  Furthermore, the MOCVD apparatus 10 includes a group III gas supply source 31 that is a source of a group III gas as a source gas containing a group III element, and a group III gas supplied from the group III gas supply source 31. As a group III gas supply amount adjusting unit capable of adjusting a supply amount of a group III gas supplied from a group III gas supply source 31 and a group III gas pipe 32 for supplying gas to the showerhead 20 The mass flow controller 33 is provided. The group III gas supply source 31 is connected to the group III gas supply unit 23 of the shower head 20 via a mass flow controller 33 by a group III gas pipe 32.

  In this embodiment, examples of the group III element include Ga (gallium), Al (aluminum), and In (indium), and examples of the group III gas containing the group III element include trimethylgallium. One or more of organic metal gases such as (TMG) or trimethylaluminum (TMA) can be used.

  Further, the MOCVD apparatus 10 includes a V group gas supply source 34 serving as a supply source of a V group gas as a source gas containing a V group element, and a V group gas supplied from the V group gas supply source 34. A group V gas supply amount adjusting unit capable of adjusting the amount of group V gas supplied from the group V gas supply source 34 and the group V gas supply source 34 A mass flow controller 36. The group V gas supply source 34 is connected to the group V gas supply unit 24 of the shower head 20 through a mass flow controller 36 by a group V gas pipe 35.

In this embodiment, examples of the group V element include N (nitrogen), P (phosphorus), and As (arsenic), and examples of the group V gas including the group V element include ammonia ( One or more of hydrogen compound gases such as NH ₃ ), phosphine (PH ₃ ), or arsine (AsH ₃ ) can be used.

  The mass flow controllers 33 and 36 are controlled by a control unit (not shown).

  In the present embodiment, a cold water supply unit 22 is provided as a cooling means between the group III gas supply unit 23 and the shower plate 21. The cold water supply unit 22 cools the shower plate 21. For this purpose, cold water is supplied from a water cooling device 38 through a cold water system pipe 37. In the present embodiment, the cold water supply unit 22 supplies cooling water. However, the present invention is not necessarily limited to water, and other liquid and gas refrigerants can be used.

  Next, the structure of the shower head 20 is demonstrated using FIG.

  As shown in FIG. 3, the shower head 20 is configured by laminating a shower plate 21, a cold water supply unit 22, a group III gas supply unit 23, and a group V gas supply unit 24 in order from the bottom. .

  Since the shower plate 21, the cold water supply unit 22, the group III group gas supply unit 23, and the group V group gas supply unit 24 are stacked, in this embodiment, the intermediate chamber in the group V group gas supply unit 24 and The group V gas in the group V gas buffer area 24b as the individual intermediate chamber is an individual gas provided through the group III gas buffer area 23b and the cold water buffer area 22b as the intermediate chamber and the individual intermediate chamber. The gas is discharged into the growth chamber 1 from a group V gas discharge hole H5 as a gas discharge hole of the shower plate 21 through a group V gas supply pipe 24c as a supply pipe.

  The group III gas in the group III gas buffer area 23b in the group III gas supply unit 23 passes through the group III gas supply pipe 23c provided through the cold water buffer area 22b as a cooling means. The gas is discharged into the growth chamber 1 from a group III gas discharge hole H3 as a gas discharge hole 21.

  Hereinafter, each will be described in detail.

  First, FIG. 4A shows a schematic plan view of an example of the shower plate 21 used in the MOCVD apparatus 10 shown in FIG.

  The shower plate 21 has a group III gas discharge hole H3 for supplying a group III gas to the growth chamber 1 and a group V gas discharge hole H5 as a gas discharge hole for supplying a group V gas. A plurality of each is formed. In the plane of the shower plate 21 (in the surface facing the susceptor 4), the group III gas discharge holes H3 and the group V gas discharge holes H5 are alternately arranged. In the example shown in FIG. 4A, the arrangement directions of the group III gas discharge holes H3 and the group V gas discharge holes H5 are a horizontal direction and a vertical direction. That is, it has a lattice shape. However, this lattice is not limited to a square lattice, and may be a diamond lattice. Further, in the shower plate 21 having the configuration shown in FIG. 4A, the area of the opening of the group III gas discharge hole H3 and the area of the opening of the group V gas discharge hole H5 are the same.

  FIG. 4B is a schematic plan view of another example of the shower plate 21. The plurality of group III-based gas discharge holes H3 and group V-based gas discharge holes H5 of the shower plate 21 have an opening ratio on the radially outer side smaller than an opening ratio on the radially inner side.

  Specifically, for example, due to the difference between the central portion 21a and the peripheral portion 21b, the hole diameter is increased at the central portion 21a and the hole diameter is decreased at the peripheral portion 21b. Thereby, the flow volume of the gas in the peripheral part 21b can be suppressed. As shown in FIG. 4B, even when the hole diameters of the group III gas discharge hole H3 and the group V gas discharge hole H5 are reduced in the peripheral portion 21b, the opening of the group III gas discharge hole H3 is provided. And the area of the opening of the group V gas discharge hole H5 are the same. Of course, also in the central portion 21a, the area of the opening of the group III gas discharge hole H3 and the area of the opening of the group V gas discharge hole H5 are the same.

  Note that the method of making the aperture ratio on the radially outer side smaller than the aperture ratio on the radially inner side is not necessarily limited to this. For example, the arrangement density of the group III gas discharge holes H3 and the group V gas discharge holes H5 in the peripheral part 21b as the outer peripheral part is set so that the group III gas discharge holes H3 and the group V in the central part 21a as the inner peripheral part. It is also possible to make it smaller than the arrangement density of the system gas discharge holes H5.

  Next, the chilled water supply unit 22 suppresses the adhesion of the reaction product to the shower plate 21 by cooling the shower plate 21 shown in FIG. 3 to a certain temperature or less, and the group III gas discharge holes H3 and V The clogging of the group gas discharge hole H5 is prevented.

  Next, each gas supply part is demonstrated.

  As shown in FIG. 3, the group III-based gas supply unit 23 serves as an outer ring flow path for uniformly guiding the group III-based gas supplied from, for example, the peripheral portion of the shower head 20 to the group III-based gas discharge hole H3. A group III gas outer ring passage 23a, a group III gas buffer area 23b, and a group III gas supply pipe 23c as an individual gas supply pipe communicating with the growth chamber 1 from the group III gas buffer area 23b. Has been. The cross section of the group III gas supply pipe 23c is not necessarily limited to a circular shape, and may be a square pipe, an elliptical pipe, or other cross sections. In the present invention, when the cold water supply unit 22 is not provided, the group III gas supply pipe 23c may not be provided. In this case, the group III gas in the group III gas buffer area 23b is discharged from the group III gas discharge hole H3.

  On the other hand, similarly, the V group gas supply unit 24 uniformly guides the reaction gas supplied from the peripheral portion of the shower head 20 to the V group gas discharge hole H5, and therefore, the V group gas outside the outer ring passage is provided. An annular flow path 24a, a V group gas buffer area 24b, and a V group gas supply pipe 24c as an individual gas supply pipe are configured. Note that the cross section of the group V gas supply pipe 24c is not necessarily limited to a circle, and may be a square pipe, an elliptical pipe, or other cross sections.

  Here, FIG. 5 is a perspective view of the group V gas outer ring flow path 24a (the group III gas outer ring flow path 23a has the same structure and will not be described).

  For example, the V-group gas supplied from the lateral direction of the V-group gas outer ring passage 24a is an inner wall with an opening having a plurality of openings HIN5 that are evenly arranged on the inner peripheral side of the V-group gas outer ring passage 24a. Are supplied to the V group gas buffer area 24b uniformly in the radial direction through the partition 24d with an opening. The V group gas in the V group gas buffer area 24b is supplied to the growth chamber 1 from the V group gas discharge hole H5 through the plurality of V group gas supply pipes 24c.

  That is, as shown in FIG. 3, a group V gas supply pipe 24c is arranged in the group III gas buffer area 23b so as not to mix the respective gases. In other words, in the plane of the group III gas buffer area 23b, the group III gas supply hole communicated from the group III gas buffer area 23b to the group III gas discharge hole H3 at the position of the group III gas discharge hole H3. A pipe 23c is disposed, and a group V gas supply pipe 24c communicating from the group V gas buffer area 24b to the group V gas discharge hole H5 is provided at the position of the group V gas discharge hole H5. It will be so forested.

  Next, the characteristic structure of the shower head 20 in the MOCVD apparatus 10 of this Embodiment is demonstrated based on FIG. 1 and said FIG. FIG. 1 is a longitudinal sectional view showing details of the internal structure of the group III gas buffer area 23b. In FIG. 1, only the right half structure of the shower head 20 is shown.

  The group III gas buffer area 23b in the shower head 20 of the present embodiment is provided with a partition wall 40 that divides the periphery of the group III gas buffer area 23b into a plurality of layers, for example, two layers.

  As a result, the group III gas is uniformly supplied from the partition 23d with the opening as the inner wall with the opening of the group III gas outer ring passage 23a to the group III gas buffer area 23b. This group III-based gas is sent to the growth chamber 1 through a plurality of group III-based gas discharge holes H3.

  At this time, as shown in FIG. 15 and FIG. 16, in the structure of the shower head 20 ′ of the comparative example, there is no partition wall 40 in the group III gas buffer area 23b. The flow rate in the central portion is slower than that in the central portion, and the amount of gas fed from the group III gas discharge hole H3 into the growth chamber 1 differs between the central portion and the peripheral portion.

  On the other hand, like the shower head 20 of the present embodiment shown in FIG. 1, by providing a partition wall 40 that partitions the periphery of the group III-based gas buffer area 23b into a plurality of regions in the stacking direction, FIG. As shown in the figure, the flow rates in the peripheral part and the central part of the group III gas buffer area 23b are substantially equal, and the amount of gas fed into the growth chamber 1 from the group III gas discharge hole H3 is different between the central part and the peripheral part. It becomes uniform. In addition, by partitioning the group III gas buffer area 23b only in the stacking direction in this way, it becomes possible to eliminate the gas staying in the vicinity of the curved portion 40a shown in FIG. 9 described later, and it is caused by the reaction of the staying gas. Deposits can be eliminated.

  In the present embodiment, it is divided into, for example, two layers which are a plurality of layers. However, the present invention is not limited to this. For example, as shown in FIG. Is possible. At this time, as shown in FIG. 7, when the partition wall 40 is provided with two or more partition walls 41 and 42 that divide the periphery of the group III-based gas buffer area 23b into three or more layers, the shower plate 21 It can be assumed that the partition wall 41 that is farther from the center extends to the center of the group III gas buffer area 23b. That is, in FIG. 7, the partition wall 41 extends to the center of the group III gas buffer area 23 b rather than the partition wall 42.

  Further, in the present embodiment, as shown in FIG. 8, of the partition walls 41 and 42, for example, the partition wall 41 is provided in a non-contact manner with a partition 23d with an opening as an inner wall with an opening. It can be. The partition wall 42 may be provided in a non-contact manner with the partition 23d with an opening. Further, the partition 40 in the case of a single partition may be provided in a non-contact manner with the opening-equipped partition 23d.

  Moreover, in this Embodiment, as shown in FIG. 9, the partition 40 has the curved part 40a bent 90 degree | times to the shower plate 21 side in the center side edge part of the group III type | system | group gas buffer area 23b. Can be. In this configuration, the bent portion 40 a of the partition wall 40 can be assumed to be in contact with the shower plate 21 at the tip.

  Thereby, as shown in FIG. 10, the direction of the flow in the group III gas buffer area 23b can be regulated in the radial direction. That is, the group III gas flows radially from the opening HIN3 of the group III gas outer ring passage 23a toward the inside of the group III gas buffer area 23b, and turbulent in the center of the group III gas buffer area 23b. However, turbulent flow can be prevented by providing the curved portion 40a, and the amount of gas fed from the group III gas discharge hole H3 to the growth chamber 1 is reduced in the group III gas buffer area 23b. It can be made uniform in the central part and the peripheral part.

  In the above configuration, as shown in FIG. 11, the partition walls 41 and 42 have curved portions 41a and 42a curved toward the shower plate 21 at the center side end of the group III gas buffer area 23b. It is also possible to do that. In this case, it is also possible to provide a curved curved portion in the partition wall 40, which is a case where there is one partition wall. Further, the bending angles of the bent portion 40a and the bent portions 41a and 42a are not necessarily 90 degrees, and may be 45 degrees or other angles, for example. Furthermore, the curved portion 40a and the curved portions 41a and 42a may be, for example, a perforated wall or a net shape.

  Moreover, in this Embodiment, the partition 40 shown in FIG. 9 has the structure which has the curved part 40a bent 90 degree | times to the shower plate 21 side in the center side edge part of the group III type | system | group gas buffer area 23b. In FIG. 12, the partition 40 can be provided at a position crossing the opening HIN3 provided in the partition 23d with opening. That is, the opening HIN3 in the adjacent region in the stacking direction can be shared or common.

  As a result, the number of gas supply ports supplied from the partition 23d with the opening of the group III gas outer ring passage 23a becomes one, the number of flow rate adjusting valves can be reduced, and the peripheral portion of the group III gas buffer area 23b can be reduced. The flow rates in the central portion are substantially equal, and the amount of gas fed from the group III-based gas discharge hole H3 to the growth chamber 1 is uniform in the central portion and the peripheral portion.

  Further, in the present embodiment, as shown in FIG. 13, the partition wall 43 may be provided so as to be inclined so as to rise toward the center of the group III gas buffer area 23b.

  As shown in FIG. 13, a curved portion 43 a that rises 90 degrees with respect to the shower plate 21 may be provided at the center side end of the group III gas buffer area 23 b of the partition wall 43. As a result, as shown in FIG. 14, it is possible to reduce the decrease in the flow velocity in the region between the peripheral portion and the central portion of the group III gas buffer area 23b, and the uniformity is improved.

  A method for growing a group III-V compound semiconductor crystal by the MOCVD method using the MOCVD apparatus 10 having the above configuration will be described.

  As shown in FIG. 2, first, the substrate 3 to be processed is placed on the susceptor 4. Thereafter, the rotation of the rotating shaft 7 causes the surface of the substrate 3 to be processed installed on the upper surface of the susceptor 4 to rotate while maintaining a state parallel to the shower plate 21, and the object to be processed via the susceptor 4 is heated by the heater 5. The substrate 3 is heated to a predetermined temperature. As shown in FIG. 1, since the partition wall 40 is provided in the group III gas buffer area 23b, the group III gas flows in a balanced manner from both the peripheral portion 21b and the central portion 21a of the shower plate 21. A plurality of group III gas discharge holes H3 are introduced into the growth chamber 1 in a direction perpendicular to the surface of the substrate 3 to be processed.

  A V group gas is introduced into the growth chamber 1 from the V group gas discharge hole H <b> 5 formed in the shower plate 21 in a direction perpendicular to the surface of the substrate 3 to be processed. As a result, a III-V compound semiconductor crystal grows on the surface of the substrate 3 to be processed. Here, the introduction amount of the group III gas and the introduction amount of the group V gas are controlled by the mass flow controllers 33 and 36 by a control unit (not shown), and each of the group III gas and the group V gas grows. It will be introduced into the chamber 1.

  The group III gas and the group V gas are introduced from the group III gas discharge holes H3 and the group V gas discharge holes H5 alternately arranged on the shower plate 21, respectively. The uneven distribution of the group III gas discharge holes H3 and the group V gas discharge holes H5 on the upper side can be reduced.

  The group III gas and the group V gas are mixed to make the concentration distribution uniform, and in combination with the heating of the substrate 3 to be processed by the heater 5, the gas phase reaction between the group III gas and the group V gas is processed. It proceeds in the vicinity of the surface of the substrate 3.

  Therefore, when the MOCVD apparatus 10 of the present embodiment is used, the group III-based gas and the group V on the surface of the substrate 3 to be processed are compared with the case where the apparatuses described in the conventional patent documents 3 to 6 are used. The uniformity of the gas phase reaction with the system gas can be improved.

  In the above description, the case where a group III gas and a group V gas are introduced has been described. However, in the present invention, a gas serving as an inert gas or a dopant source together with a group III gas and a group V gas. Etc. may be introduced into the growth chamber 1.

  In the above description, the case where the group III gas discharge hole H3 and the group V gas discharge hole H5 are respectively circular has been described, but in the present invention, the group III gas discharge hole H3 and the group V system are used. The shape of the gas discharge hole H5 is not particularly limited, and can be, for example, rectangular or elliptical. In the present invention, the group III gas discharge hole H3 and the group V gas discharge hole H5 may have the same shape, or at least a part thereof may be different.

  In the above description, the case where one substrate to be processed 3 is installed has been described. However, in the present invention, not only one substrate 3 but also a plurality of substrates to be processed may be installed.

  Further, 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. For example, when the entire MOCVD apparatus is in a reverse state, that is, a type in which the raw material gas is blown out from below is used.

  As described above, in the MOCVD apparatus 10 and the vapor phase growth method of the present embodiment, the source gas is supplied into the growth chamber 1 from the shower head 20 provided opposite to the growth chamber 1 in the form of a shower. Vapor phase growth is performed on the substrate 3 to be processed. The shower head 20 is provided in a ring shape on the outer periphery, and the group III gas outer ring passage 23a and the group V gas outer ring passage 24a, and the group III gas outer ring passage 23a and group V are introduced. Opening partitions 23d and 24d having an opening HIN3 and an opening HIN5 through which the source gas passes and the inside of the system gas outer ring passage 24a, and the group III gas of the source gas located inside the opening partitions 23d and 24d A plurality of group III gas discharge holes H3 and group V gas discharges located downstream of the buffer area 23b and group V gas buffer area 24b and the group III gas buffer area 23b and group V gas buffer area 24b And a shower plate 21 having a hole H5.

  Therefore, the group III gas and the V group gas source gas are supplied from the group III gas outer ring passage 23a and the group V gas outer ring passage 24a to the group III gas buffer area 23b and the group V gas buffer area 24b. By passing through, the space above the shower plate 21 can be effectively utilized, and the entire MOCVD apparatus 10 can be reduced in thickness.

  By the way, when the source gas is passed from the group III gas outer ring channel 23a and the group V gas outer ring channel 24a to the group III gas buffer area 23b and the group V gas buffer area 24b, The gas flow velocity in the peripheral portion is large, and the gas flow velocity becomes smaller as it goes deeper into the center of the group III gas buffer area 23b. As a result, the raw material gas discharged from the plurality of gas discharge holes H3 of the shower plate 21 to the growth chamber 1 has a large gas flow velocity in the peripheral portion 21b of the shower plate 21, and becomes deeper into the central portion 21a of the shower plate 21. The gas flow rate is reduced. As a result, the source gas is not uniformly supplied to the substrate 3 to be processed in the growth chamber 1.

  Therefore, in the present embodiment, the group III gas buffer area 23b is provided with a partition wall 40 that partitions the periphery of the group III gas buffer area 23b into a plurality of layers in the stacking direction. That is, one partition 40 or a plurality of partitions 41 and 42 are provided in parallel to the shower plate 21 in the peripheral portion on the outer peripheral side of the center portion of the group III-based gas buffer area 23b.

  For this reason, the source gas passing through the counter shower plate 21 side of the partition walls 40, 41, and 42 in the periphery of the group III gas buffer area 23b enters the center of the group III gas buffer area 23b and then enters the shower plate. 21 is discharged into the growth chamber 1 from a plurality of group III-based gas discharge holes H3 in the central portion. On the other hand, the raw material gas passing through the shower plate 21 side of the partition walls 40, 41, and 42 in the peripheral part of the group III gas buffer area 23b is in the peripheral part of the shower plate 21 in the peripheral part of the group III gas buffer area 23b. Are discharged into the growth chamber 1 from a plurality of group III gas discharge holes H3.

  As a result, the source gas is discharged into the growth chamber 1 from the plurality of group III gas discharge holes H3 and group V gas discharge holes H5 in a balanced manner from both the peripheral portion 21b and the central portion 21a of the shower plate 21. become.

  Therefore, when the source gas is introduced from the peripheral portion of the shower head 20, the gas concentration distribution on the surface of the substrate 3 to be processed in the growth chamber 1 can be made uniform, and the film thickness and composition ratio can be improved. An MOCVD apparatus 10 and a vapor phase growth method that can be provided can be provided.

  In the MOCVD apparatus 10 of the present embodiment, since two or more partition walls 41 and 42 that partition the periphery of the group III gas buffer area 23b into three or more layers are provided, the group III gas outer ring channel 23a is provided. The group III gas buffer area 23b is divided into three or more layers. Here, in the present embodiment, the partition wall 41 farther from the shower plate 21 extends to the center of the group III gas buffer area 23b. For this reason, the source gas flowing through the layer farther from the shower plate 21 goes deeper into the center of the group III-based gas buffer area 23b, and the depth is divided according to the number of partition walls 41 and 42. As a result, the source gas can be discharged from the plurality of group III gas discharge holes H3 into the growth chamber 1 in a balanced manner from the peripheral portion 21b to the central portion 21a of the shower plate 21. This configuration is advantageous for increasing the size of the MOCVD apparatus 10.

  In the MOCVD apparatus 10 of the present embodiment, the partition wall 43 is provided so as to be inclined away from the shower plate 21 toward the center of the group III gas buffer area 23b. In the present embodiment, the partition wall 43 is provided to be inclined so as to rise as it goes toward the center of the group III-based gas buffer area 23b.

  As a result, the flow rate of the source gas flowing through the layer away from the shower plate 21 increases as it enters the center of the group III gas buffer area 23b, and enters the center of the group III gas buffer area 23b. It becomes easy to do. Therefore, when the source gas is introduced from the peripheral portion of the shower head 20, the gas concentration distribution on the surface of the substrate 3 to be processed in the growth chamber 1 can be made uniform, and the film thickness and composition ratio can be improved. it can.

  Further, in the MOCVD apparatus 10 of the present embodiment, the partition wall 40 can be provided at a position crossing the opening HIN3 provided in the partition 23d with opening. That is, when the source gas flows into the group III gas buffer area 23b from the group III gas outer ring passage 23a through the opening of the partition 23d with an opening, adjacent in the stacking direction in the peripheral part of the group III gas buffer area 23b. The layer has a single opening HIN3, and the opening HIN3 is shared by adjacent layers in the stacking direction.

  As a result, two flow rate adjusting portions (not shown) for adjusting the flow rate of the source gas flowing through each layer in the stacking direction in the peripheral portion of the group III gas buffer area 23b are shared by one, not shown. Flow control valves can be reduced. As a result, a simple structure can be obtained, and it can be manufactured at a low cost. In this embodiment, two of the flow rate adjustment units are shared by one. However, the present invention is not necessarily limited to this, and if the non-contact portion has two stages, three of them are shared by one. become. That is, in the present invention, a plurality of the flow rate adjusting units can be shared by one.

  Further, in the MOCVD apparatus 10 of the present embodiment, the partition walls 40, 41, and 42 can be provided in a non-contact manner with the apertured partition 23d. Thereby, in a non-contact area | region, a flow path resistance can be made small by the part which there is no partition 40 * 41 * 42. As a result, the flow rate of the source gas in this non-contact region increases, and the source gas can be easily penetrated into the central portion of the group III gas buffer area 23b. Even with this configuration, two of the flow rate adjusting units (not shown) are shared by one, and the number of flow rate adjusting valves (not shown) can be reduced. In the present invention, a plurality of the flow rate adjusting units can be shared by one. Moreover, the area of the partition 40, 41, 42 can be reduced, and the material cost of the partition 40, 41, 42 can be reduced.

  Further, in the MOCVD apparatus 10 of the present embodiment, the partition walls 40, 41, 42, and 43 are bent at the center side end of the group III gas buffer area 23b, and are bent or curved toward the shower plate 21 side. It is possible to have 41a, 42a, 43a.

  Thereby, the source gas flowing through the layer on the shower plate 21 side in the peripheral part of the group III gas buffer area 23b can be forcibly directed to the shower plate 21 side. For this reason, it is only necessary to consider the flow rate when the partition walls 40, 41, 42, and 43 are discharged from the group III-based gas discharge holes H3 to the growth chamber 1 for each planar region, so that the flow rate of the source gas can be easily controlled. Become.

  Further, in the MOCVD apparatus 10 of the present embodiment, the bent portions 40a, 41a, 42a, and 43a of the partition walls 40, 41, and 42 can be assumed to be in contact with the shower plate 21 on the shower plate 21 side. It is. When the intermediate chambers are laminated in three or more stages, the curved portions 40a, 41a, 42a, and 43a are in contact with the intermediate chamber surface.

  Accordingly, it is only necessary to take into account the flow rate when discharging from the group III-based gas discharge hole H3 to the growth chamber 1 in each plane region of each partition wall 40, 41, and 42, so that it is easy to control the flow rate of the source gas. It becomes.

  Further, in the MOCVD apparatus 10 of the present embodiment, the intermediate chamber is composed of a group III gas buffer area 23b and a group V gas buffer area 24b as individual intermediate chambers arranged in a plurality of layers. The group III gas buffer area 23b on the shower plate 21 side in the buffer area 23b and the group V gas buffer area 24b includes a group V gas on the side opposite to the shower plate 21 than the group III gas buffer area 23b on the shower plate 21 side. A V-group gas supply pipe 24c as an individual gas supply pipe communicating with the gas buffer area 24b is provided therethrough. The anti-shower plate 21 side is the opposite side to the shower plate 21 side.

  In this way, when the group V gas supply pipe 24c is provided in a forest in the group III gas buffer area 23b, the source gas is passed from the group III gas outer ring passage 23a to the group III gas buffer area 23b. In this case, the gas flow rate in the peripheral part of the group III gas buffer area 23b is large, and the gas flow rate is particularly small due to the resistance of the group V gas supply pipe 24c that grows deeper into the center of the group III gas buffer area 23b. Become.

  In this regard, in the present embodiment, the partition walls 40, 41, 42, and 43 that partition the periphery of the group III-based gas buffer area 23b into a plurality of layers in the stacking direction are provided. The gas is discharged into the growth chamber 1 from the plurality of group III-based gas discharge holes H3 and group V-based gas discharge holes H5 in a balanced manner from both the peripheral portion 21b and the central portion 21a.

  Therefore, when the source gas is introduced from the peripheral portion of the shower head 20, the gas concentration distribution on the surface of the substrate 3 to be processed in the growth chamber 1 can be made uniform, and the film thickness and composition ratio can be improved. The MOCVD apparatus 10 that can be provided can be provided.

  Further, in the MOCVD apparatus 10 of the present embodiment, the cold water buffer area 22b is provided between the shower plate 21 and the group III gas buffer area 23b. Thereby, when the source gas is introduced from the peripheral portion of the shower head 20, the source gas can be cooled in the cold water buffer area 22b and the gas concentration distribution on the surface of the substrate 3 to be processed in the growth chamber 1 is made uniform. Therefore, it is possible to provide the MOCVD apparatus 10 that can improve the film thickness and the composition ratio.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. Configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are given the same reference numerals, and explanation thereof is omitted.

  The MOCVD apparatus 10 of the present embodiment is different in that the partition wall through holes are formed in the partition walls 40, 41, 42, and 43 of the first embodiment.

  That is, in the MOCVD apparatus 10 of the present embodiment, as shown in FIG. 18, the partition wall 40 is formed with a partition wall through hole 40b as a through hole into which the group V gas supply pipe 24c can be inserted. The partition wall through-hole 40b may be provided with a clearance with respect to the outer diameter of the group V gas supply pipe 24c.

  As a result, the partition wall 40 can be detached, the assembly and replacement of the partition wall 40 can be facilitated, and the group III gas buffer area 23b as an intermediate chamber of the shower head 14 can have a simple structure. The device 10 can be manufactured at low cost.

  Further, in the present embodiment, as shown in FIG. 19, when a partition wall through hole into which the group V gas supply pipe 24c can be inserted is provided, the partition wall penetration at the periphery of the group III gas buffer area 23b as an intermediate chamber is provided. The partition wall through-hole 40d at the center portion can be made the partition wall 40 having a larger through-hole area as an opening area than the hole 40c.

  Thereby, on the free end side of the partition wall 40, the increase in the partial flow velocity at which the source gas passing through the side opposite to the shower plate of the partition wall 40 and the source gas passing through the shower plate side of the partition wall 40 is suppressed to a minimum, and the turbulent flow Can be mitigated. Therefore, the gas concentration distribution on the surface of the substrate to be processed 3 in the growth chamber 1 can be made more uniform.

  In the MOCVD apparatus 10 of the present embodiment, as shown in FIG. 20, even when the partition wall through hole and the V group gas supply pipe 24c are integrated without clearance, the V group gas supply in the partition wall 40 is provided. It is possible to provide partition through holes 40e and 40f other than the region of the tube 24c. Even in this case, the partition wall through hole 40f at the center of the group III gas buffer area 23b is more through-hole than the partition wall through hole 40e at the periphery of the group III gas buffer area 23b as an intermediate chamber. The opening area per unit area can be increased.

  Accordingly, as in the above reason, the flow velocity of the portion where the source gas passing through the counter shower plate side of the partition wall 40 and the source gas passing through the shower plate side of the partition wall 40 merge on the free end side of the partition wall 40. Can be minimized, and the generation of turbulence can be mitigated. As a result, the gas concentration distribution on the substrate 3 to be processed in the growth chamber 1 can be made more uniform.

  In addition, although said description was the case where the partition through-hole and the V group type gas supply pipe 24c were integrated without a clearance, it is not necessarily restricted to this. That is, the configuration of the partition wall through hole 40b in the case where the partition wall through hole and the group V gas supply pipe 24c shown in FIG. 18 are integrated without clearance, and the configuration of FIG. 20 and the configuration of FIG. 18 are combined. It may be complex.

  Further, in the above description, the partition 40 that divides the group III gas buffer area 23b as an intermediate chamber into a plurality of layers, for example, two layers has been described. However, the present invention is not necessarily limited thereto.

  For example, as shown in FIG. 21, in the partition walls 41 and 42 that divide the group III gas buffer area 23b into a plurality of layers, for example, three layers, a group V gas supply pipe 24c can be inserted into each of the partition walls 41 and 42. The partition wall through holes 41c, 41d, and 41e and the partition wall through holes 42c and 42d may be formed. The through-hole area of the partition wall through holes 41d and 42d4 in the central portion of the group III gas buffer area 23b is more than the partition wall through holes 41c and 42c in the periphery of the group III gas buffer area 23b as an intermediate chamber. Is preferably formed large.

  In the partition walls 41 and 42, when the partition wall through hole 41c and the partition wall through hole 42c through which the same group V gas supply pipe 24c passes are compared, the partition wall through hole 42c of the partition wall 42 on the shower plate 21 side is anti-shower. It is preferable that the opening area is larger than the partition wall through hole 41c of the partition wall 41 on the plate 21 side. Thereby, it is possible to suppress the upper-layer source gas from directly flowing into the shower plate 21.

  In addition, in at least one of the partition walls 41 and 42, the partition wall through hole may be provided outside the region of the group V gas supply pipe 24c. In this case, the partition wall through hole in the central portion of the intermediate chamber is formed to have a larger opening area per unit area of the through hole than the partition wall through hole in the peripheral portion of the group III gas buffer area 23b. Is preferred.

  In addition, about the shape of a partition through-hole, it does not necessarily restrict to circular, A square tube, an elliptical tube, or another cross section may be sufficient.

  In this way, in the MOCVD apparatus 10 of the present embodiment, the partition wall through holes 40b to 40f, 41c to 41e, and 42c to 42d are formed in the partition walls 40, 41, 42, and 43.

  This avoids a rapid confluence of the source gases on the free ends of the partition walls 40, 41, 42 and 43, that is, in the center of the group III gas buffer area 23b, and the gas concentration on the substrate 3 to be processed in the growth chamber 1 Fine adjustment can be made as appropriate so as to make the distribution uniform.

  Further, when the intermediate chamber is divided into a plurality of layers using a plurality of source gases, the partition walls 40, 41, 42, and 43 have a group V gas as a through pipe that penetrates the lower group III gas buffer area 23b. The supply pipe 24c can be passed, and the assembly and replacement of the partition walls 40, 41, 42 and 43 can be facilitated, and the group III gas buffer area 23b as an intermediate chamber of the shower head 20 has a simple structure. The MOCVD apparatus 10 can be manufactured at a low cost.

  In the MOCVD apparatus 10 of the present embodiment, the opening area per unit area of the partition wall through holes 40b to 40f, 41c to 41e, and 42c to 42d in the partition walls 40, 41, and 42 is a group III gas as an intermediate chamber. It becomes larger toward the center than the periphery of the buffer area 23b.

  That is, when there are no partition wall through holes 40b to 40f, 41c to 41e, 42c to 42d in the partition walls 40, 41 and 42, the free ends of the partition walls 40, 41 and 42, that is, the center of the group III gas buffer area 23b. In the part, the increase in the flow velocity at the portion where the raw material gas passing through the side opposite to the shower plate of the partition walls 40, 41 and 42 and the raw material gas passing through the shower plate side of the partition walls 40, 41 and 42 is abruptly changed. Flow may occur.

  In this regard, in this embodiment, the opening area per unit area of the partition wall through holes 40b to 40f, 41c to 41e, and 42c to 42d in the partition walls 40, 41, and 42 is larger than that of the periphery of the group III gas buffer area 23b. It gets bigger toward the center. For this reason, the source gas passing through the partition plate 40, 41, 42 on the side opposite to the shower plate gradually flows into the source gas passing through the partition plate on the shower plate side as the source gas moves toward the center of the intermediate chamber.

  As a result, on the free end side of the partition walls 40, 41, 42, the portion where the source gas passing through the counter shower plate side of the partition walls 40, 41, 42 and the source gas passing through the shower plate side of the partition walls 40, 41, 42 merge The rapid increase of the flow velocity and the generation of turbulent flow can be mitigated.

  Therefore, the gas concentration distribution on the surface of the substrate to be processed 3 in the growth chamber 1 can be made uniform, and the film thickness and composition ratio can be improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

  The present invention is a vapor phase growth method such as a vertical MOCVD apparatus using a shower plate that introduces a gas into the space above the shower plate from the periphery and supplies a reaction gas to the substrate surface from a plurality of gas discharge holes of the shower plate. Available for equipment.

DESCRIPTION OF SYMBOLS 1 Growth chamber 2 Reactor 3 Substrate to be processed 4 Susceptor 10 MOCVD apparatus (vapor phase growth apparatus)
20 Shower head (gas supply means)
21 Shower plate 21a Center (inner circumference)
21b Peripheral part (outer peripheral part)
22 Chilled water supply unit 22b Chilled water buffer area (cooling means)
23 III Group Gas Supply Unit 23a III Group Gas Outer Ring Channel (Outer Ring Channel)
23b Group III gas buffer area (intermediate room, individual intermediate room)
23c III group gas supply pipe 23d Partition with opening (inner wall with opening)
24 V group gas supply unit 24a V group gas outer ring channel (outer ring channel)
24b Group V gas buffer area (intermediate room, individual intermediate room)
24c Group V gas supply pipe (individual gas supply pipe)
24d partition with opening (inner wall with opening)
40, 41, 41 ', 42, 43 Partition 40a, 41a, 42a, 43a Curved portion 40b, 40c, 40d Partition through hole 41c, 41d, 41e Partition through hole 42c, 42d Partition through hole H3 III group gas discharge hole ( Gas discharge hole)
H5 V group gas discharge hole (gas discharge hole)
HIN3 opening HIN5 opening

Claims (12)

In a vapor phase growth apparatus for performing vapor phase growth on a substrate to be processed in the growth chamber by supplying a source gas into the growth chamber in a shower form from a gas supply means provided facing the growth chamber.
The gas supply means includes
An outer ring passage that is annularly provided on the outer periphery and into which the source gas is introduced;
An inner wall with an opening provided inside the outer ring flow path and having an opening through which the source gas passes;
An intermediate chamber of source gas located inside the inner wall with the opening;
A shower plate having a plurality of gas discharge holes located on the downstream side of the intermediate chamber,
A vapor phase growth apparatus characterized in that the intermediate chamber is provided with a partition wall that partitions the peripheral portion of the intermediate chamber into a plurality of layers in the stacking direction. The partition is
It consists of two or more that divide the periphery of the intermediate chamber into three or more layers,
2. The vapor phase growth apparatus according to claim 1, wherein the partition wall farther from the shower plate extends to the center of the intermediate chamber.   The vapor phase growth apparatus according to claim 1, wherein a through hole is formed in the partition wall. The opening area per unit area of the through hole in the partition wall is
4. The vapor phase growth apparatus according to claim 1, wherein the vapor deposition apparatus is larger toward a center than a peripheral part of the intermediate chamber.   5. The vapor phase growth apparatus according to claim 1, wherein the partition wall is provided so as to be inclined away from the shower plate toward the center of the intermediate chamber.   6. The vapor phase growth apparatus according to claim 1, wherein the partition wall is provided at a position crossing an opening provided on the inner wall with the opening.   7. The vapor phase growth apparatus according to claim 1, wherein the partition wall is provided in a non-contact manner with the inner wall with the opening.   8. The vapor phase growth according to claim 1, wherein the partition wall has a bent portion that is bent or curved toward the shower plate side at a center side end portion of the intermediate chamber. apparatus.   9. The vapor phase growth apparatus according to claim 8, wherein the bent portion of the partition wall is in contact with the surface of the intermediate chamber on the shower plate side or the shower plate. The intermediate chamber is composed of a plurality of stacked individual intermediate chambers that are separated by a separation plate and respectively store different types of source gases,
In the individual intermediate chamber on the shower plate side in the individual intermediate chamber arranged in a stacked manner, the individual intermediate chamber on the shower plate side connected to a plurality of gas discharge holes for supplying different kinds of source gases in the shower plate 10. The vapor phase growth apparatus according to claim 1, further comprising an individual gas supply pipe penetrating the individual intermediate chamber on the side opposite to the shower plate.   The vapor phase growth apparatus according to any one of claims 1 to 10, wherein cooling means is provided between the shower plate and the intermediate chamber. In a vapor phase growth method for performing vapor phase growth on a substrate to be processed in the growth chamber by supplying a raw material gas into the growth chamber from a gas supply means provided facing the growth chamber in a shower shape,
Introducing the source gas into the outer ring channel of the gas supply means provided in a ring shape on the outer periphery,
A plurality of layers in the stacking direction at the periphery of the intermediate chamber from the opening of the inner wall with an opening provided inside the outer ring channel to the intermediate chamber of the source gas located inside the inner wall with the opening Through the part partitioned by a partition,
A vapor phase growth method comprising performing a vapor phase growth by supplying a raw material gas in a shower shape from a plurality of gas discharge holes of a shower plate located downstream of the intermediate chamber into a growth chamber.

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