Epitaxial growth apparatus and epitaxial growth method

Abstract

The invention provides epitaxial growth equipment and an epitaxial growth method, and belongs to the technical field of power electronics. The epitaxial growth equipment comprises a reaction chamber, a top cover, a first spraying head and a second spraying head, the top cover comprises a cover plate and a surrounding baffle, the surrounding baffle and the first spraying head are both located on the same surface of the cover plate, the surrounding baffle surrounds the first spraying head, and the second spraying head is located on the same surface of the cover plate. The second spraying head is located on the side wall, close to the first spraying head, of the surrounding baffle, the spraying direction of the first spraying head is perpendicular to the cover plate, and the spraying direction of the second spraying head is parallel to the cover plate; the reaction chamber is provided with an opening end, the top cover covers the opening end, and one end, far away from the cover plate, of the enclosure plate is opposite to the opening end. The problem of peeling of the stone mill disc and the top cover can be solved, and the epitaxial growth efficiency is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and in particular to an epitaxial growth device and an epitaxial growth method. Background Art

[0002] The reaction chamber is the core part of the MOCVD (Metal-organic Chemical Vapor Deposition) epitaxial growth equipment. When designing the reaction chamber, it is necessary to avoid the occurrence of wall jets and turbulence in the reaction chamber, and ensure that only laminar flow exists, so as to achieve uniform distribution of air flow and temperature in the reaction chamber, which is conducive to uniform growth over a large area. Therefore, the design of the reaction chamber has a crucial impact on the growth effect.

[0003] In the related art, a shower head is provided in the reaction chamber of the epitaxial growth equipment, and the MO source is sprayed out through the shower head so that the MO source can adhere to the graphite disk in the reaction chamber to achieve the growth of the epitaxial layer.

[0004] However, when epitaxially growing the SiN layer, the millstone and the top cover on the top of the reaction chamber usually peel off. After peeling, the millstone and the top cover need to be baked, and the epitaxial growth equipment needs to be restored after being put back into the reaction chamber. These processes take 2 to 3 days, and therefore, will affect the efficiency of epitaxial growth. Summary of the invention

[0005] The embodiments of the present disclosure provide an epitaxial growth device and an epitaxial growth method, which can improve the problem of peeling of the millstone and the top cover and improve the efficiency of epitaxial growth. The technical solution is as follows:

[0006] An embodiment of the present disclosure provides an epitaxial growth device, which includes: a reaction chamber, a top cover, a first spray head and a second spray head, the top cover includes a cover plate and a baffle plate, the baffle plate and the first spray head are both located on the same surface of the cover plate, the baffle plate surrounds the first spray head, the second spray head is located on the side wall of the baffle plate close to the first spray head, the spray direction of the first spray head is perpendicular to the cover plate, and the spray direction of the second spray head is parallel to the cover plate; the reaction chamber has an open end, the top cover is disposed on the open end, and an end of the baffle plate away from the cover plate is opposite to the open end.

[0007] In an implementation of the embodiment of the present disclosure, there are multiple second spray heads, and the multiple second spray heads are evenly distributed on the side wall of the baffle plate in a circumferential direction.

[0008] In another implementation of the embodiment of the present disclosure, the epitaxial growth equipment also includes a graphite disk, a rotating shaft and a first motor, the reaction chamber also has a closed end opposite to the open end, the graphite disk is located in the reaction chamber, one end of the rotating shaft is coaxially connected to the graphite disk, and the other end of the rotating shaft passes through the closed end, and the first motor is located outside the reaction chamber and is transmission-connected to the other end of the rotating shaft.

[0009] In another implementation of the embodiment of the present disclosure, the side wall of the baffle plate has an annular limiting groove, and the second shower head is slidably arranged in the annular limiting groove; the epitaxial growth equipment also includes a first driving assembly, and the first driving assembly is used to drive the second shower head to slide in the annular limiting groove.

[0010] In another implementation of the embodiment of the present disclosure, the first driving component includes: a first sliding block, a first roller and a second motor, the first roller, the second motor and the second spray head are all located on the first sliding block, the second motor is used to drive the first roller to rotate, the first sliding block is slidably set in the annular limit groove, and the first roller is in contact with the bottom of the annular limit groove.

[0011] In another implementation of the embodiment of the present disclosure, a surface of the first sliding block close to the annular limit groove has an installation groove, a rotatable shaft is installed on the groove wall of the installation groove, the first roller is coaxially fixed outside the rotating shaft, the second motor is transmission-connected to the rotating shaft, and the second spray head is located on the surface of the first sliding block away from the annular limit groove.

[0012] In another implementation of the embodiment of the present disclosure, the surface of the cover plate has a spiral sliding groove, the extension trajectory of the spiral sliding groove is a flat spiral line, and the first spray head is slidably arranged in the spiral sliding groove; the epitaxial growth equipment also includes a second driving assembly, and the second driving assembly is used to drive the first spray head to slide in the spiral sliding groove.

[0013] In another implementation of the embodiment of the present disclosure, the second driving component includes: a second sliding block, a second roller and a third motor, the second roller, the third motor and the first spray head are all located on the second sliding block, the third motor is used to drive the second roller to rotate, the second sliding block is slidably arranged in the spiral sliding groove, and the second roller is in contact with the bottom of the spiral sliding groove; the second roller is a magnetic material piece, and the cover plate is a magnetic material piece or a ferromagnetic metal material piece.

[0014] An embodiment of the present disclosure provides an epitaxial growth method, which is implemented using the epitaxial growth equipment as described above, including: placing a substrate on the surface of a graphite disk; closing a first shower head and opening a second shower head to spray an MO source into a reaction chamber to grow an epitaxial layer on the surface of the substrate; opening the first shower head and closing the second shower head to spray an MO source into the reaction chamber to grow a SiN layer on the surface of the epitaxial layer.

[0015] In another implementation of the embodiment of the present disclosure, the thickness uniformity of the epitaxial layer is less than 0.8%, and the thickness of the SiN layer is less than or equal to 100 nm.

[0016] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure include at least:

[0017] The epitaxial growth device provided by the embodiment of the present disclosure includes a reaction chamber and a top cover, a first shower head is arranged on the cover plate of the top cover, and the spray direction of the first shower head is perpendicular to the cover plate, and a second shower head is arranged on the side wall of the baffle plate of the top cover, and the spray direction of the second shower head is parallel to the cover plate. The top cover is arranged at the open end of the reaction chamber to cover the reaction chamber.

[0018] When preparing epitaxial wafers, the epitaxial growth equipment places the substrate into the reaction chamber, and then controls the second shower head to start spraying the MO source, and closes the first shower head. In this way, the MO source will flow in the horizontal direction, covering the surface of the substrate, so that an epitaxial layer with good thickness uniformity can be grown. Next, the first shower head is controlled to start spraying the MO source, and the second shower head is closed. In this way, the MO source will flow downward in a direction perpendicular to the substrate and directly cover the entire substrate surface, that is, when the MO source flows, there is a tendency to press the substrate downward. Therefore, when growing SiN, the method of spraying the MO source with the first shower head can avoid the problem of peeling of the millstone and the top cover, so there is no need to bake the graphite disk and the top cover, which is beneficial to improve the efficiency of epitaxial growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 is a schematic structural diagram of an epitaxial growth device provided by an embodiment of the present disclosure;

[0021] Figure 2 is a distribution diagram of a second shower head provided by an embodiment of the present disclosure;

[0022] Figure 3 is a partial schematic diagram of an epitaxial growth device provided by an embodiment of the present disclosure;

[0023] Figure 4 is a schematic diagram of a cover plate provided by an embodiment of the present disclosure;

[0024] Figure 5 is a schematic diagram of a second driving assembly provided by an embodiment of the present disclosure;

[0025] Figure 6 It is a flow chart of an epitaxial growth method provided in an embodiment of the present disclosure.

[0026] The descriptions of the marks in the figure are as follows:

[0027] 10. Reaction chamber;

[0028] 20. Top cover; 21. Cover plate; 210. Spiral sliding groove; 22. Enclosing plate; 220. Annular limiting groove;

[0029] 31. First spray head; 32. Second spray head;

[0030] 41. graphite disk; 42. rotating shaft; 43. first motor;

[0031] 51. first sliding block; 510. mounting slot; 52. first roller; 53. second motor;

[0032] 61. Second sliding block; 62. Second roller; 63. Third motor. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0034] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", "top", "bottom" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] In the related art, the reaction chamber of the epitaxial growth equipment includes a horizontal reaction chamber and a vertical reaction chamber. For the horizontal reaction chamber, during epitaxial growth, the substrate is placed on a horizontal stone millstone, the direction of the MO source introduction is horizontal to the substrate, and the reaction gas flows horizontally over the substrate. Among them, the graphite disk will also spin, which greatly improves the thickness uniformity of the epitaxial layer and the uniformity of the Al% component of the barrier layer.

[0036] However, when growing SiN layers in horizontal reaction chambers, the millstone and top cover are prone to peeling. Even when growing a thinner SiN layer, for example, when the thickness of the SiN layer is less than 5nm, peeling will occur. After peeling, the millstone needs to be baked, and the machine needs to be restored after being put back into the reaction chamber. These processes take 2 to 3 days and are not suitable for large-scale mass production of Si-based HEMTs (High Electron Mobility Transistors) with SiN film layers.

[0037] For vertical reaction chambers, during epitaxial growth, the direction of MO source introduction is perpendicular to the substrate, and the reaction gas directly covers the entire substrate surface. In this reaction chamber structure, the reaction gas will press down on the substrate, thereby avoiding the problem of peeling. Although the vertical reaction chamber can grow SiN layers with a thickness of 0nm to 100nm, the thickness uniformity of the epitaxial layer grown in the vertical reaction chamber is >0.8% and the uniformity of the Al% component of the barrier layer is >1.0%, which is worse than that of the horizontal reaction chamber.

[0038] In the related art, the epitaxial layer can also be grown in a horizontal reaction chamber first until it grows to the barrier layer, and then cooled and transferred out to a multi-wafer box. Then it is taken to a vertical reaction chamber to continue growing the SiN layer. Although this method takes into account the thickness uniformity of the epitaxial layer of the epitaxial wafer, the Al% uniformity of the barrier layer, and the growth of the SiN layer, it also avoids the problem of peeling of the millstone and the top cover in the horizontal reaction chamber. However, in the process of taking out the epitaxial wafer and placing it in the vertical reaction chamber to continue growing the SiN layer, the epitaxial wafer will be exposed to the air, and water vapor will be generated on the surface of the epitaxial wafer, affecting the interface state; and the process of transferring the epitaxial wafer, the cooling time of the horizontal reaction chamber, and the heating process of the vertical reaction chamber are time-consuming and labor-intensive, waste energy, and are not conducive to mass production.

[0039] To this end, an embodiment of the present disclosure provides an epitaxial growth device. Figure 1 Schematic diagram of the structure of an epitaxial growth device provided by an embodiment of the present disclosure. Figure 1 As shown, the epitaxial growth equipment includes: a reaction chamber 10, a top cover 20, a first shower head 31 and a second shower head 32. The top cover 20 includes a cover plate 21 and a baffle plate 22. The baffle plate 22 and the first shower head 31 are both located on the same surface of the cover plate 21. The baffle plate 22 surrounds the first shower head 31. The second shower head 32 is located on the side wall of the baffle plate 22 close to the first shower head 31. The spraying direction of the first shower head 31 is perpendicular to the cover plate 21, and the spraying direction of the second shower head 32 is parallel to the cover plate 21.

[0040] like Figure 1 As shown, the reaction chamber 10 has an open end, the top cover 20 is covered on the open end, and the end of the baffle plate 22 away from the cover plate 21 is opposite to the open end.

[0041] The epitaxial growth device provided by the embodiment of the present disclosure includes a reaction chamber 10 and a top cover 20, a first shower head 31 is arranged on the cover plate 21 of the top cover 20, and the spray direction of the first shower head 31 is perpendicular to the cover plate 21, and a second shower head 32 is arranged on the side wall of the baffle plate 22 of the top cover 20, and the spray direction of the second shower head 32 is parallel to the cover plate 21. The top cover 20 is arranged on the open end of the reaction chamber 10 to cover the reaction chamber 10.

[0042] When preparing an epitaxial wafer, the epitaxial growth device places the substrate into the reaction chamber 10, and then controls the second shower head 32 to start spraying the MO source, and closes the first shower head 31. In this way, the MO source will flow in the horizontal direction, covering the surface of the substrate, so that an epitaxial layer with good thickness uniformity can be grown. Next, the first shower head 31 is controlled to start spraying the MO source, and the second shower head 32 is closed. In this way, the MO source will flow downward in a direction perpendicular to the substrate and directly cover the entire substrate surface, that is, when the MO source flows, there is a tendency to press the substrate downward. Therefore, when growing SiN, the method of spraying the MO source with the first shower head 31 can avoid the problem of peeling of the stone millstone and the top cover 20, so that there is no need to bake the graphite disk 41 and the top cover 20, which is conducive to improving the efficiency of epitaxial growth.

[0043] The epitaxial growth equipment in the disclosed embodiment not only ensures the uniformity of the thickness of the epitaxial layer, but also avoids the problem of easy peeling of the grown SiN layer. In addition, in the process of continuously growing the epitaxial layer and the SiN layer, it is not necessary to transfer the epitaxial wafer from one reaction chamber 10 to another reaction chamber 10, which can avoid the epitaxial wafer from being exposed to the air, and prevent the generation of water vapor on the surface of the epitaxial wafer from affecting the interface state, which is conducive to mass production.

[0044] Optionally, there are multiple second spray heads 32 , and the multiple second spray heads 32 are evenly distributed on the side wall of the baffle plate 22 in the circumferential direction.

[0045] By arranging a plurality of second shower heads 32 on the side wall of the baffle plate 22, the reaction gas of the MO source can be expanded horizontally from different directions to the surface of the substrate, which can further improve the thickness uniformity of the epitaxial layer and help to increase the growth rate of the epitaxial layer.

[0046] For example, Figure 2 FIG. 1 is a schematic diagram of the distribution of a second shower head 32 provided in an embodiment of the present disclosure. Figure 2 As shown, the epitaxial growth equipment includes two second shower heads 32 , and the two second shower heads 32 are symmetrically arranged on the side wall of the baffle plate 22 .

[0047] Among them, Figure 2 As shown, the interval angle between the two second shower heads 32 is 180°.

[0048] In this way, two opposite second spray heads 32 are arranged on the side wall of the top cover 20, and the MO source spraying angles of the two second spray heads 32 can be designed so that the MO source sprayed by the two second spray heads 32 at various positions on the millstone is the same. Figure 2 In the part indicated by the dotted line, the MO source sprayed out by the two opposite second spray heads 32 can make the amount of MO source and gas flowing to each position of the millstone consistent, which is beneficial to improving uniformity.

[0049] Alternatively, if Figure 1 As shown, the epitaxial growth equipment also includes a graphite disk 41, a rotating shaft 42 and a first motor 43. The reaction chamber 10 also has a closed end opposite to the open end. The graphite disk 41 is located in the reaction chamber 10. One end of the rotating shaft 42 is coaxially connected to the graphite disk 41, and the other end of the rotating shaft 42 passes through the closed end. The first motor 43 is located outside the reaction chamber 10 and is transmission-connected to the other end of the rotating shaft 42.

[0050] The output shaft of the first motor 43 is in driving connection with the rotating shaft 42 , so that the power of the first motor 43 can be transmitted to the rotating shaft 42 , thereby driving the rotating shaft 42 to rotate.

[0051] Exemplarily, the output shaft of the first motor 43 is coaxially connected to the rotating shaft 42. A groove is provided at the end of the output shaft of the first motor 43, and the other end of the rotating shaft 42 is inserted into the groove, and the output shaft of the first motor 43 and the groove can be circumferentially fixed by a keyway, so that when the output shaft of the first motor 43 rotates, the rotating shaft 42 can be driven to rotate, so as to drive the graphite disk 41 to rotate together.

[0052] Exemplarily, the output shaft of the first motor 43 is connected to the rotating shaft 42 through a gear transmission. A gear is sleeved on the end of the output shaft of the first motor 43, and a gear is sleeved on the other end of the rotating shaft 42, and the two gears are meshed. In this way, when the output shaft of the first motor 43 rotates, the rotating shaft 42 can be driven to rotate, so as to drive the graphite disk 41 to rotate together.

[0053] Figure 3 FIG. 1 is a partial schematic diagram of an epitaxial growth device provided by an embodiment of the present disclosure. Figure 3 As shown, the side wall of the baffle plate 22 has an annular limiting groove 220 , and the second spray head 32 is slidably disposed in the annular limiting groove 220 .

[0054] The epitaxial growth device further includes a first driving component, which is used to drive the second shower head 32 to slide in the annular limiting groove 220 .

[0055] Exemplarily, the baffle plate 22 is in a circular ring shape, and the annular limiting groove 220 is also in a circular ring shape, so that the second spray head 32 can slide smoothly in the annular limiting groove 220 .

[0056] In the disclosed embodiment, the second spray head 32 is controlled to slide in the annular limit groove 220 by the first driving assembly, so that the second spray head 32 can be controlled to move to various positions on the side wall of the baffle plate 22. In this way, the second spray head 32 can spray the MO source in the horizontal direction from different directions, which can further improve the thickness uniformity of the epitaxial layer and is beneficial to improving the growth rate of the epitaxial layer.

[0057] Alternatively, if Figure 3As shown, the first driving assembly includes: a first sliding block 51, a first roller 52 and a second motor 53. The first roller 52, the second motor 53 and the second spray head 32 are all located on the first sliding block 51. The second motor 53 is used to drive the first roller 52 to rotate. The first sliding block 51 is slidably set in the annular limit groove 220, and the first roller 52 is in contact with the bottom of the annular limit groove 220.

[0058] like Figure 3 As shown, limiting strips can be provided on both sides of the annular limiting groove 220 to reduce the opening width of the annular limiting groove 220. Accordingly, the first sliding block 51 can be in an I-shape, so that after the first sliding block 51 is placed in the annular limiting groove 220, the limiting strips can prevent the first sliding block 51 from falling out of the annular limiting groove 220.

[0059] In the above implementation, the first roller 52 is mounted on the first sliding block 51, and the second motor 53 is also disposed on the first sliding block 51. By driving the first roller 52 to rotate with the second motor 53, the first sliding block 51 can be driven to slide in the annular limiting groove 220, thereby controlling the second spray head 32 to move to various positions on the side wall of the baffle plate 22.

[0060] Alternatively, if Figure 3 As shown, the surface of the first sliding block 51 close to the annular limit groove 220 has an installation groove 510, and a rotatable shaft is installed on the groove wall of the installation groove 510. The first roller 52 is coaxially fixed outside the shaft, the second motor 53 is connected to the shaft in transmission, and the second spray head 32 is located on the surface of the first sliding block 51 away from the annular limit groove 220.

[0061] For example, Figure 3 As shown, two first rollers 52 are arranged in the installation groove 510, and the two first rollers 52 are fixedly sleeved outside the rotating shaft. In this way, a plurality of first rollers 52 are arranged to contact the bottom of the annular limiting groove 220, which can increase the contact area between the first rollers 52 and the annular limiting groove 220, so that the first rollers 52 can more easily drive the second spray head 32 to move along the annular limiting groove 220 of the baffle plate 22.

[0062] For example, Figure 3 As shown, the first sliding block 51 has a transmission groove, which passes through the first sliding block 51, and a gear is fixedly sleeved in the middle of the rotating shaft. A gear is fixedly sleeved on the output shaft of the second motor 53, and the gear is located in the transmission groove. The gear on the output shaft of the second motor 53 meshes with the gear on the rotating shaft, which enables the second motor 53 to drive the rotating shaft to rotate, thereby driving the first roller 52 to rotate, so as to drive the second spray head 32 to move along the annular limiting groove 220 of the baffle plate 22.

[0063] Figure 4is a schematic diagram of a cover plate 21 provided in an embodiment of the present disclosure. Figure 4 As shown, the surface of the cover plate 21 has a spiral sliding groove 210 , the extension track of the spiral sliding groove 210 is in the shape of a flat spiral line, and the first spray head 31 is slidably disposed in the spiral sliding groove 210 .

[0064] The epitaxial growth device further includes a second driving component, which is used to drive the first shower head 31 to slide in the spiral sliding groove 210 .

[0065] In the disclosed embodiment, the first spray head 31 is controlled to slide in the annular limit groove 220 by the second driving component, so that the first spray head 31 can be controlled to move along the spiral sliding groove 210, so that the first spray head 31 can move to different positions of the cover plate 21 and spray the graphite disk 41 at different positions, so that each area on the graphite disk 41 can evenly receive the reaction gas of the MO source, which is beneficial to improving the thickness uniformity of the epitaxial material grown on the substrate, and each position on the graphite disk 41 can be subjected to a strong downward pressure, which can effectively prevent the top cover 20 and the graphite disk 41 from peeling.

[0066] Figure 5 is a schematic diagram of a second drive assembly provided by an embodiment of the present disclosure. Figure 5 As shown, the second driving assembly includes: a second sliding block 61, a second roller 62 and a third motor 63. The second roller 62, the third motor 63 and the first spray head 31 are all located on the second sliding block 61. The third motor 63 is used to drive the second roller 62 to rotate. The second sliding block 61 is slidably set in the spiral sliding groove 210, and the second roller 62 is in contact with the bottom of the spiral sliding groove 210.

[0067] In the above implementation, the second roller 62 is mounted on the second sliding block 61, and the third motor 63 is also disposed on the second sliding block 61. By driving the second roller 62 to rotate with the third motor 63, the second sliding block 61 can be driven to slide in the spiral sliding groove 210, thereby achieving the purpose of controlling the first spray head 31 to move in various areas of the cover plate 21.

[0068] The second roller 62 is made of a magnetic material, and the cover plate 21 is made of a magnetic material or a ferromagnetic metal material.

[0069] For example, the second roller 62 is a roller made of magnets, and the roller can be fixedly mounted on the transmission shaft, and the third motor 63 is connected to the transmission shaft to drive the second roller 62 to roll. At the same time, the cover plate 21 can be an iron plate, so that the second roller 62 can be magnetically adsorbed on the iron plate to prevent the first spray head 31 from falling off from the top cover 20, thereby improving the connection reliability.

[0070] Figure 61 is a flow chart of an epitaxial growth method provided by an embodiment of the present disclosure. Figure 6 As shown, the epitaxial growth method is implemented using the epitaxial growth equipment as described above, and the epitaxial growth method includes:

[0071] Step S11 : placing a substrate on the surface of the graphite disk 41 .

[0072] Illustratively, the substrate may be a silicon substrate or a sapphire substrate.

[0073] Step S12: close the first shower head 31 and open the second shower head 32 to spray MO source into the reaction chamber 10 to grow an epitaxial layer on the surface of the substrate.

[0074] Optionally, when the substrate is a silicon substrate, the epitaxial layer may include a nucleation layer, a superlattice layer and a barrier layer sequentially stacked on the silicon substrate.

[0075] Exemplarily, the nucleation layer may be an AlN layer, and the thickness of the AlN layer is 100 nm to 300 nm.

[0076] For example, the superlattice layer may include a plurality of AlGaN layers and a plurality of AlN layers alternately stacked, the sum of the thickness of each AlGaN layer and the AlN layer is 10 nm to 30 nm, and the superlattice layer may include 20 to 100 AlGaN layers and AlN layers.

[0077] Exemplarily, the barrier layer may be an AlGaN layer, and the thickness of the AlGaN layer is 15 nm to 20 nm.

[0078] Optionally, when the substrate is a sapphire substrate, the epitaxial layer may include a nucleation layer, a high resistance layer, a channel layer and a barrier layer sequentially stacked on the sapphire substrate.

[0079] Exemplarily, the nucleation layer may be an AlN layer, and the thickness of the AlN layer is 100 nm to 300 nm.

[0080] Exemplarily, the high resistance layer may be a GaN layer, and the thickness of the GaN layer ranges from 1 nm to 100 nm.

[0081] Exemplarily, the channel layer may be a GaN layer, and the thickness of the GaN layer ranges from 50 nm to 200 nm.

[0082] Exemplarily, the barrier layer may be an AlGaN layer, and the thickness of the AlGaN layer is 15 nm to 20 nm.

[0083] In step S12, the second shower head 32 is used to horizontally spray the MO source to grow a barrier layer with an Al% composition uniformity of less than 1.5%, and the thickness uniformity of the epitaxial layer is also less than 0.8%.

[0084] Step S13: Open the first shower head 31 and close the second shower head 32 to spray MO source into the reaction chamber 10 to grow a SiN layer on the surface of the epitaxial layer.

[0085] In the disclosed embodiment, a SiN layer is also grown on the epitaxial layer in order to have a better interface state, reduce dynamic resistance, and improve transistor reliability. In addition, the first shower head 31 is used to vertically spray the MO source, which can exert downward pressure on the graphite layer, so that even if a thicker SiN layer is grown, the peeling problem is not likely to occur.

[0086] Optionally, the thickness of the SiN layer is less than or equal to 100 nm. Exemplarily, the thickness of the SiN layer is 50 nm.

[0087] The above does not limit the present disclosure in any form. Although the present disclosure has been disclosed as above through the embodiments, it is not used to limit the present disclosure. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present disclosure. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure still falls within the scope of the technical solution of the present disclosure.

Claims

1. An epitaxial growth device, characterized in that: The epitaxial growth device comprises: a reaction chamber (10), a top cover (20), a first shower head (31) and a second shower head (32); the top cover (20) comprises a cover plate (21) and a baffle plate (22); the baffle plate (22) and the first shower head (31) are both located on the same surface of the cover plate (21); the baffle plate (22) surrounds the first shower head (31); the second shower head (32) is located on a side wall of the baffle plate (22) close to the first shower head (31); the spraying direction of the first shower head (31) is perpendicular to the cover plate (21); and the spraying direction of the second shower head (32) is parallel to the cover plate (21); The reaction chamber (10) has an open end, the top cover (20) is arranged on the open end, and an end of the enclosure plate (22) away from the cover plate (21) is opposite to the open end.

2. The epitaxial growth device according to claim 1, characterized in that: There are a plurality of the second spray heads (32), and the plurality of the second spray heads (32) are evenly distributed circumferentially on the side wall of the baffle plate (22).

3. The epitaxial growth device according to claim 1, characterized in that: The epitaxial growth device further comprises a graphite disk (41), a rotating shaft (42) and a first motor (43); the reaction chamber (10) further comprises a closed end opposite to the open end; the graphite disk (41) is located in the reaction chamber (10); one end of the rotating shaft (42) is coaxially connected to the graphite disk (41); the other end of the rotating shaft (42) passes through the closed end; the first motor (43) is located outside the reaction chamber (10) and is transmission-connected to the other end of the rotating shaft (42).

4. The epitaxial growth device according to any one of claims 1 to 3, characterized in that: The side wall of the baffle plate (22) has an annular limiting groove (220), and the second spray head (32) is slidably arranged in the annular limiting groove (220); The epitaxial growth device further comprises a first driving component, wherein the first driving component is used to drive the second shower head (32) to slide in the annular limiting groove (220).

5. The epitaxial growth device according to claim 4, characterized in that: The first driving assembly comprises: a first sliding block (51), a first roller (52) and a second motor (53); the first roller (52), the second motor (53) and the second spray head (32) are all located on the first sliding block (51); the second motor (53) is used for driving the first roller (52) to rotate; the first sliding block (51) is slidably disposed in the annular limiting groove (220), and the first roller (52) is in contact with the bottom of the annular limiting groove (220).

6. The epitaxial growth device according to claim 5, characterized in that: The surface of the first sliding block (51) close to the annular limiting groove (220) is provided with an installation groove (510), a rotatable shaft is installed on the groove wall of the installation groove (510), the first roller (52) is coaxially fixedly sleeved outside the rotating shaft, the second motor (53) is transmission-connected to the rotating shaft, and the second spray head (32) is located on the surface of the first sliding block (51) away from the annular limiting groove (220).

7. The epitaxial growth device according to any one of claims 1 to 3, characterized in that: The surface of the cover plate (21) is provided with a spiral sliding groove (210), the extension track of the spiral sliding groove (210) is in the shape of a flat spiral line, and the first spray head (31) is slidably arranged in the spiral sliding groove (210); The epitaxial growth device further comprises a second driving component, which is used to drive the first shower head (31) to slide in the spiral sliding groove (210).

8. The epitaxial growth device according to claim 7, characterized in that: The second driving assembly comprises: a second sliding block (61), a second roller (62) and a third motor (63); the second roller (62), the third motor (63) and the first spray head (31) are all located on the second sliding block (61); the third motor (63) is used to drive the second roller (62) to rotate; the second sliding block (61) is slidably disposed in the spiral sliding groove (210), and the second roller (62) is in contact with the bottom of the spiral sliding groove (210); The second roller (62) is made of a magnetic material, and the cover plate (21) is made of a magnetic material or a ferromagnetic metal material.

9. An epitaxial growth method, characterized in that: The epitaxial growth method is implemented using the epitaxial growth device according to any one of claims 1 to 8, comprising: placing a substrate on a surface of a graphite disk; Close the first shower head and open the second shower head to spray MO source into the reaction chamber to grow an epitaxial layer on the surface of the substrate; The first shower head is turned on and the second shower head is turned off to spray a MO source into the reaction chamber to grow a SiN layer on the surface of the epitaxial layer.

10. The epitaxial growth method according to claim 9, characterized in that: The thickness uniformity of the epitaxial layer is less than 0.8%, and the thickness of the SiN layer is less than or equal to 100 nm.

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