Gallium nitride layer manufacturing apparatus and method for manufacturing gallium nitride layer

Abstract

To suppress reduction in the quality of a GaN layer.SOLUTION: A method for manufacturing a GaN layer comprises: including a state determination part 400 for determining a state in the inside of a growth container 100; heating the inside of the growth container 100 at a temperature higher than that of growing a GaN layer 122 by a heating device 140 until the state determination part 400 determines that only foreign matters less than a predetermined amount exist in the growth container 100; controlling the heating device 140 so that the inside of the growth container 100 is at a temperature of growing the GaN layer 122 when the state determination part 400 determines that only the foreign matters less than the predetermined amount exist in the growth container; and supplying first and second material gases on a seed substrate 121 to grow a GaN layer 122.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a GaN layer manufacturing apparatus and a GaN layer manufacturing method for growing a GaN layer on a seed substrate made of gallium nitride (hereinafter, also simply referred to as GaN). [Background technology]

[0002] Conventionally, a GaN layer manufacturing apparatus and a manufacturing method thereof have been proposed, which use a hydride vapor phase epitaxy to grow a GaN layer on a seed substrate made of GaN (see, for example, Patent Document 1). Specifically, the manufacturing apparatus includes a growth apparatus on which a seed substrate is placed and on which a GaN layer is grown, and a generation apparatus that generates gallium trichloride gas as a raw material gas for growing the GaN layer. The manufacturing apparatus also includes a first supply pipe that connects the growth apparatus and the generation apparatus and supplies the gas generated by the generation apparatus to the growth apparatus, and a second supply pipe that supplies ammonia gas as a raw material gas for growing the GaN layer to the growth apparatus.

[0003] The growth apparatus has a growth vessel in which a seed substrate is placed, and is configured so that gallium trichloride gas generated in the generation device is supplied into the growth vessel through a first supply pipe, and ammonia gas is supplied into the growth vessel through a second supply pipe.

[0004] The generating device includes a generating vessel in which metallic gallium is disposed. The generating vessel includes a first space in which metallic gallium is disposed, and a second space communicating with the first space. The generating vessel also includes a first induction pipe for guiding chlorine gas to the first space, and a second induction pipe for guiding chlorine gas to the second space.

[0005] In the generator, when chlorine gas is introduced from the first induction pipe, the metallic gallium reacts with the chlorine gas to generate gallium monochloride gas, as shown in the reaction of Chemical Formula 1 below.

[0006] (Chemical formula 1) Ga+1 / 2Cl2 → GaCl In addition, in the generation device, when chlorine gas is introduced into the generation vessel from the second induction pipe, the gallium monochloride gas and the chlorine gas react with each other to generate gallium trichloride gas, as shown in the following chemical formula 2.

[0007] (Chemical formula 2)GaCl+Cl2→GaCl3 In such a GaN layer manufacturing apparatus, gallium trichloride gas and ammonia gas are supplied onto the seed substrate, and a GaN layer is grown by the reaction of Chemical Formula 3 below.

[0008] (C3)GaCl3+NH3→GaN+3HCl [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 5787324 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the above-mentioned GaN layer manufacturing apparatus, when the GaN layer is repeatedly grown, there is a possibility that an abnormal state occurs in which foreign matter is retained in the space inside the growth vessel or foreign matter is attached to the wall surface of the growth vessel. Note that the foreign matter here includes a material containing gallium. In this case, if the GaN layer is grown in this state, the quality of the GaN layer may be degraded.

[0011] In view of the above, an object of the present invention is to provide a GaN layer manufacturing apparatus and a GaN layer manufacturing method that can suppress deterioration in the quality of the GaN layer. [Means for solving the problem]

[0012] In order to achieve the above object, claim 1 provides a GaN layer manufacturing apparatus for growing a GaN layer (122) by supplying a gallium-based gas and an ammonia-based gas onto a seed substrate (121), the apparatus comprising: a growth apparatus (10) having a cylindrical growth vessel (100) in which a GaN layer is grown in a hollow portion (101a) constituting a reaction chamber; a base (120) disposed in the hollow portion of the growth vessel and on which a seed substrate on which a GaN layer is grown is disposed; a first supply pipe (310) for supplying a first source gas containing gallium trichloride gas as a gallium-based gas for growing the GaN layer to the growth apparatus; a second supply pipe (320) for supplying a second source gas containing an ammonia-based gas for growing the GaN layer to the growth apparatus; a heating device (140) for heating the inside of the growth vessel; and a state determination unit (400) for determining a state inside the growth vessel, The heating device is The state determination unit determines that only the amount of foreign matter present in the growth vessel is less than a predetermined amount. in Higher temperature than the temperature at which the GaN layer is grown So that Heating the growth vessel It is adjusted to When the state determination unit determines that only the amount of foreign matter present in the growth vessel is less than a predetermined amount, 、 The temperature inside the growth chamber is adjusted to a temperature suitable for growing the GaN layer. After the temperature inside the growth chamber is adjusted to the temperature required for growing the GaN layer using a heating device, The first source gas and the second source gas are supplied onto the seed substrate to grow a GaN layer. Equipped with a control unit (423) .

[0013] According to this, before growing the GaN layer, the growth vessel is heated to a temperature higher than the temperature at which the GaN layer 122 is grown (i.e., high-temperature cleaning is performed) until it is determined that only less than a predetermined amount of foreign matter is present in the growth vessel. This makes it possible to suppress deterioration in the quality of the GaN layer.

[0014] Claim 6 is a method for manufacturing a GaN layer using the GaN layer manufacturing apparatus of claim 1, which includes the steps of heating the inside of the growth vessel to a temperature higher than the temperature at which the GaN layer is grown using a heating device until a state determination unit determines that only less than a predetermined amount of foreign matter is present in the growth vessel, adjusting the heating device so that the inside of the growth vessel is at a temperature at which the GaN layer is grown after the state determination unit determines that only less than a predetermined amount of foreign matter is present in the growth vessel, and supplying a first source gas and a second source gas onto a seed substrate to grow a GaN layer.

[0015] According to this, before growing the GaN layer, the growth vessel is heated to a temperature higher than the temperature at which the GaN layer 122 is grown (i.e., high-temperature cleaning is performed) until it is determined that only less than a predetermined amount of foreign matter is present in the growth vessel. This makes it possible to suppress deterioration in the quality of the GaN layer.

[0016] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view of a GaN layer manufacturing apparatus according to a first embodiment. [Diagram 2] FIG. 11 is a schematic cross-sectional view of a GaN layer manufacturing apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0019] (First embodiment) The first embodiment will be described with reference to the drawings. First, the configuration of a GaN layer manufacturing apparatus will be described with reference to Fig. 1. The GaN layer manufacturing apparatus shown in Fig. 1 is installed with the up-down direction of the paper surface of Fig. 1 as the top-to-bottom direction, and grows a GaN layer 122 on a seed substrate 121.

[0020] 1, the GaN layer manufacturing apparatus includes a growth apparatus 10 for growing a GaN layer 122, and a generation apparatus 20 for generating gallium trichloride gas as a source gas for growing the GaN layer 122. The GaN layer manufacturing apparatus also includes first to third supply pipes 310 to 330 for supplying various gases for growing the GaN layer 122 to the growth apparatus 10. The GaN layer manufacturing apparatus further includes a state determination unit 400 for determining the state of a growth vessel 100, which will be described later.

[0021] The growth apparatus 10 includes a growth vessel 100, a heating vessel 110, a base 120, a shaft 131, a rotation displacement mechanism 132, a heating device 140, and the like.

[0022] The growth vessel 100 has a cylindrical tube portion 101 having a hollow portion 101a that constitutes a reaction chamber, and a first lid portion 102 and a second lid portion 103 that are provided in the tube portion 101 and close the hollow portion 101a. The tube portion 101 is made of quartz glass or the like, and is cylindrical in this embodiment. The first lid portion 102 and the second lid portion 103 are made of SUS or the like, and the first lid portion 102 is provided at an end portion of the tube portion 101 that is the top side, and the second lid portion 103 is provided at an end portion of the tube portion 101 that is the bottom side. The growth vessel 100 has a structure in which other components for growing the GaN layer 122 are arranged in the hollow portion 101a, and the pressure in the hollow portion 101a can be reduced by vacuuming.

[0023] The first lid portion 102 of this embodiment has a main portion 102a which constitutes the majority of the first lid portion 102, and a window portion 102c which closes a through hole 102b formed in the approximate center of the main portion 102a. The window portion 102c is made of a material capable of transmitting the irradiation light La irradiated from the irradiation portion 410 described later and the reflected light Lb, for example, SiO2.

[0024] The growth vessel 100 is also provided with first to third supply pipes 310 to 330 for supplying various gases for growing the GaN layer 122. In this embodiment, the first lid 102 is provided with the first to third supply pipes 310 to 330. Specifically, the first lid 102 is provided with a first supply pipe 310 for supplying gallium trichloride gas into the growth vessel 100 as a gallium-based gas for growing the GaN layer 122 generated by the generation device 20. The first lid 102 is provided with a second supply pipe 320 for supplying ammonia gas into the growth vessel 100 as an ammonia-based gas for growing the GaN layer 122 together with the gallium trichloride gas. The first lid 102 is provided with a third supply pipe 330 for supplying nitrogen gas into the growth vessel 100 as a carrier gas.

[0025] In this embodiment, the first supply pipe 310 and the second supply pipe 320 are arranged such that one end is located inside the heating container 110 described below. On the other hand, the third supply pipe 330 is arranged such that one end is located closer to the first lid 102 than one ends of the first supply pipe 310 and the second supply pipe 320. In other words, the first to third supply pipes 310 to 330 are arranged such that the gas supplied from the first and second supply pipes 310 and 320 is easily caused to flow downward (i.e., toward the seed substrate 121 described below) by the gas supplied from the third supply pipe 330.

[0026] The first supply pipe 310 is provided with one end on the growth apparatus 10 side and the other end on the opposite side to the generation apparatus 20. In other words, the first supply pipe 310 is arranged to connect the growth apparatus 10 and the generation apparatus 20. The first supply pipe 310 has a smaller cross-sectional area normal to the gas flow direction than the generation vessel 200 described later. Although not shown, the second supply pipe 320 and the third supply pipe 330 have one end on the growth apparatus 10 and the other end on the opposite side to the respective gas supply sources.

[0027] Furthermore, the growth vessel 100 is provided with an exhaust port 104 for exhausting unreacted gases and the like that have not contributed to the growth of the GaN layer 122. In this embodiment, the exhaust port 104 is provided in the portion of the growth vessel 100 on the second lid 103 side.

[0028] The heating container 110 is made of, for example, alumina, zirconia, pyrolytic carbon, graphite, or the like, and is formed in a cylindrical shape having a hollow portion 110a. The heating container 110 is provided on the first lid portion 102 so that various gases from the first to third supply pipes 310 to 330 are supplied into the hollow portion 110a.

[0029] Pedestal 120 is a member on which seed substrate 121 made of GaN for growing GaN layer 122 is placed, and is placed below heating vessel 110. Pedestal 120 is made of a material that is difficult to thermally etch, such as graphite whose surface is coated with a high-melting point metal carbide such as PbN, SiC, TaC, or NbC. Seed substrate 121 is attached to one surface 120a of pedestal 120 located on the first to third supply pipes 310 to 330 side, and GaN layer 122 is grown on the surface of seed substrate 121.

[0030] In this embodiment, as described later, GaN layer 122 is grown by supplying gallium trichloride gas and ammonia gas onto seed substrate 121. It has been reported that when gallium trichloride gas is used to grow GaN layer 122, GaN layer 122 grows easily when the growth surface of seed substrate 121 is a nitrogen surface, and does not grow easily when the growth surface of seed substrate 121 is a gallium surface. Therefore, in this embodiment, seed substrate 121 is arranged so that the growth surface of GaN layer 122 is a nitrogen surface. In other words, seed substrate 121 is arranged so that the surface opposite to pedestal 120 is a nitrogen surface.

[0031] In addition, the pedestal 120 has a shaft 131 connected to a surface opposite to the surface on which the seed substrate 121 is disposed. The pedestal 120 is rotated with the rotation of the shaft 131, and is displaced together with the shaft 131 as the shaft 131 is displaced along the axial direction of the growth vessel 100 (i.e., the vertical direction in the plane of the paper in FIG. 1). The shaft 131, like the pedestal 120, is made of a material that is difficult to be thermally etched, and is made of, for example, graphite or the like having a surface coated with a high-melting point metal carbide such as PbN, SiC, TaC, or NbC.

[0032] Rotational displacement mechanism 132 is connected to shaft 131, and is a member that rotates and displaces shaft 131. Rotational displacement mechanism 132 adjusts the position of shaft 131 (i.e., seed substrate 121) so that the temperature of the growth surface of GaN layer 122 can be adjusted to a temperature suitable for growth as GaN layer 122 grows. Although not particularly limited, rotational displacement mechanism 132 in this embodiment rotates shaft 131 so that pedestal 120 rotates at least 200 times per minute.

[0033] Heating device 140 heats the inside of heating vessel 110 and growth vessel 100, and is configured with a heating coil such as an induction heating coil or a direct heating coil, and is arranged to surround the periphery of growth vessel 100. Heating device 140 of this embodiment is driven so that the periphery of seed substrate 121 becomes approximately 1000 to 1300° C. when growing GaN layer 122. In this embodiment, the driving of heating device 140 is adjusted by control unit 423, which will be described later.

[0034] The generating device 20 includes a generating vessel 200 and a heating device 240. The generating vessel 200 includes a cylindrical tube portion 201 having a hollow portion 201a, and a first lid portion 202 and a second lid portion 203 provided in the tube portion 201 to close the hollow portion 201a. The tube portion 201 is made of quartz glass or the like, and is cylindrical in this embodiment. The first lid portion 202 and the second lid portion 203 are made of SUS or the like. The first lid portion 202 is provided at an end of the tube portion 201 opposite to the side to which the first supply pipe 310 is connected, and the second lid portion 203 is provided at an end of the tube portion 201 to which the first supply pipe 310 is connected. The generating vessel 200 is structured such that the pressure in the hollow portion 201a can be reduced by vacuuming, similar to the growth vessel 100.

[0035] The generating vessel 200 is provided with a partition wall 213 that partitions the hollow portion 201a into a first space 211 on the first lid portion 202 side and a second space 212 on the second lid portion 203 side. However, this partition wall 213 is formed so as to maintain communication between the first space 211 and the second space 212. In other words, the partition wall 213 is provided so as not to completely partition the first space 211 and the second space 212.

[0036] Metallic gallium 220 is disposed in the first space 211. In this embodiment, the second space 212 is provided with a partition wall 214 for increasing the wall surface that comes into contact with the gallium monochloride gas and chlorine gas generated in the first space 211 as described later.

[0037] The generation vessel 200 is also provided with a first induction pipe 231 and a second induction pipe 232 for inducing chlorine gas into the generation vessel 200. In this embodiment, the first induction pipe 231 is provided in the first cover portion 202 so as to be able to induce chlorine gas into the first space 211. The second induction pipe 232 is provided in the tube portion 201 so as to be able to induce chlorine gas into the second space 212.

[0038] The heating device 240 heats the inside of the generating vessel 200, and is, for example, a resistance heater or the like, and is arranged around the generating vessel 200. The heating device 240 of this embodiment is driven by appropriately adjusting the location and density so that the first space 211 is hotter than the second space 212. For example, the heating device 240 of this embodiment is arranged and driven so that the first space 211 is about 800 to 900°C and the temperature of the second lid part 203 side of the second space 212 is about 150°C when the GaN layer 122 is grown. The part of the heating device 240 that heats the second space 212 is arranged and driven so that the temperature is gradually lowered from the part on the first space 211 side toward the second lid part 203 side. More specifically, the second space 212 is heated so that the gallium trichloride gas exists as a gas and has a part at a temperature at which the gallium monochloride gas solidifies. In this embodiment, the second space 212 is heated so that the portion on the second lid portion 203 side where the first supply pipe 310 is provided reaches that temperature, as described below.

[0039] In generation apparatus 20, the other end of first supply pipe 310 is provided on second lid 203. Although not shown, a heating device is also disposed around first supply pipe 310. First supply pipe 310 is heated to, for example, about 150° C. when growing GaN layer 122.

[0040] In this embodiment, the state determination unit 400 includes an irradiation unit 410 and a determination unit 420. In this embodiment, the irradiation unit 410 is configured to irradiate irradiation light La, which is visible light, and irradiates, for example, laser light having a wavelength of about 400 to 760 nm. The irradiation unit 410 is arranged at a position where it can irradiate the irradiation light La into the growth vessel 100 through the window 102c and where the reflected light Lb reflected in the growth vessel 100 can pass through the window 102c.

[0041] The determination unit 420 includes a light receiving unit 421, an imaging unit 422, a control unit 423, etc. The light receiving unit 421 is composed of a photodiode or the like, and is disposed at a position where it can receive reflected light Lb that is the irradiation light La that is irradiated from the irradiation unit 410.

[0042] The imaging section 422 is composed of a CCD camera or the like, and captures at least one of the irradiated light La and the reflected light Lb.

[0043] The control unit 423 is connected to the heating device 140, the irradiation unit 410, the light receiving unit 421, the imaging unit 422, etc., and is configured to have a CPU (not shown) and storage units such as a ROM, a RAM, and a non-volatile RAM. CPU is an abbreviation for Central Processing Unit, ROM is an abbreviation for Read Only Memory, RAM is an abbreviation for Random Access Memory, and ECU is an abbreviation for Electronic Control Unit.

[0044] The control unit 423 realizes various control operations by the CPU reading and executing programs (i.e., each routine described below) from the ROM or non-volatile RAM. Note that the storage unit such as the ROM or non-volatile RAM stores in advance various data (e.g., initial values, lookup tables, maps, etc.) used when executing the programs. Also, the storage medium such as the ROM is a non-transient substantial storage medium.

[0045] In this embodiment, the control unit 423 controls the driving of the heating device 140 and also judges the state inside the growth vessel 100. That is, when the growth vessel 100 is in an abnormal state where a large amount of foreign matter is retained or attached thereto (hereinafter, simply referred to as an abnormal state inside the growth vessel 100), the width (i.e., thickness) of the irradiated light La and the reflected light Lb changes inside the growth vessel 100, and the intensity (i.e., components) of the reflected light Lb changes.

[0046] Therefore, the control unit 423 adjusts the driving of the heating device 140 to heat the growth vessel 100 to a temperature equal to or higher than the growth temperature of the GaN layer 122 (for example, 1350° C.), thereby performing high-temperature cleaning of the inside of the growth vessel 100. Then, the control unit 423 controls the irradiation unit 410 to irradiate the inside of the growth vessel 100 with the irradiation light La. After that, the control unit 423 compares the measured intensity of the reflected light Lb received by the light receiving unit 421 with the intensity threshold range, and if it is determined that the measured intensity is not within the intensity threshold range, it determines that the inside of the growth vessel 100 is in an abnormal state. In addition, the control unit 423 measures the width of at least one of the irradiation light La and the reflected light Lb from the image pickup result captured by the image pickup unit 422, compares the measured width with the width threshold range, and if it is determined that the measured width is not within the width threshold range, it determines that the inside of the growth vessel 100 is in an abnormal state.

[0047] 1 illustrates the GaN layer 122 grown on the seed substrate 121 for easy understanding of the GaN layer 122, but in reality, the GaN layer 122 has not yet been grown when the state inside the growth vessel 100 is determined. In this embodiment, the irradiation light La is irradiated into the growth vessel 100 so that the irradiation light La is reflected by the seed substrate 121. However, the irradiation light La may be irradiated into the growth vessel 100 so that it is reflected by, for example, the heating vessel 110, the pedestal 120, or the like.

[0048] When the control unit 423 determines that the inside of the growth vessel 100 is in an abnormal state, the control unit 423 continues the high-temperature cleaning by extending the heating time of the heating device 140, increasing the heating temperature, etc., until the amount of foreign matter in the growth vessel 100 becomes less than a predetermined amount and returns to a normal state. When the control unit 423 determines that the inside of the growth vessel 100 is in an abnormal state for a predetermined period of time, the control unit 423 may notify the operator of that fact through an alarm device (not shown) or the like.

[0049] The above is the configuration of the GaN layer manufacturing apparatus in this embodiment. Next, a method for manufacturing the GaN layer 122 using the above GaN layer manufacturing apparatus will be described.

[0050] First, the above-mentioned GaN layer manufacturing apparatus is prepared, and seed substrate 121 is placed on one surface 120a of pedestal 120. In this embodiment, seed substrate 121 is placed so that the growth surface of GaN layer 122 is the nitrogen surface, as described above. Then, pedestal 120 is rotated via shaft 131 by rotation displacement mechanism 132, and the position of pedestal 120 is adjusted. Also, when GaN layer 122 is being grown, the height of the pedestal is adjusted in accordance with the growth rate of GaN layer 122. This keeps the height of the growth surface of the GaN layer almost constant, making it possible to effectively control the temperature distribution of the growth surface temperature.

[0051] Next, in this embodiment, the state inside the growth container 100 is judged using the state judgment unit 400. In this embodiment, as described above, the irradiation unit 410 irradiates the inside of the growth container 100 with the irradiation light La, and the state inside the growth container 100 is judged based on the measurement results of the light receiving unit 421 and the imaging unit 422.

[0052] In this embodiment, the state inside the growth vessel 100 is judged with the supply of gas stopped from the first to third supply pipes 310 to 330. The abnormality judgment inside the growth vessel 100 may be performed every time the GaN layer 122 is grown, or may be performed every time the GaN layer 122 is grown a predetermined number of times.

[0053] Next, the operation of the heating device 140 is adjusted so that the temperature around the seed substrate 121 arranged in the growth vessel 100 is about 1000 to 1300°C. The heating device 240 is also driven so that the first space 211 in the generation vessel 200 is about 800 to 900°C and the portion of the second space 212 on the second lid part 203 side is about 150°C. Furthermore, although not shown, the heating devices arranged around these are driven so that the first supply pipe 310 is also about 150°C.

[0054] Next, chlorine gas is introduced from the first induction pipe 231 and the second induction pipe 232 into the generation device 20. As a result, in the first space 211, the metal gallium 220 reacts with the chlorine gas to generate gallium monochloride gas. In addition, as the gallium monochloride gas flows into the second space 212, the gallium monochloride gas reacts with the chlorine gas introduced into the second space 212 to generate gallium trichloride gas. Then, the gallium trichloride gas is supplied to the growth device 10 through the first supply pipe 310. In this case, the second space 212 of this embodiment is provided with a partition wall 214. Therefore, the gas introduced into the second space 212 is more likely to collide with the partition wall 214 as a high-temperature portion and the flow distance becomes longer. Therefore, it is possible to suppress the gallium monochloride gas from remaining without reacting with the chlorine gas.

[0055] Ammonia gas is supplied to growth vessel 100 from second supply pipe 320, and carrier gas is supplied to growth vessel 100 from third supply pipe 330. The supply of ammonia gas is preferably started after heating device 140 is driven, when the temperature around seed substrate 121 is 500° C. or lower to prevent nitrogen loss. As a result, ammonia gas and gallium trichloride gas flow and are supplied to seed substrate 121, and GaN layer 122 is grown on the surface of seed substrate 121.

[0056] In addition, the second space 212 of this embodiment is heated so as to have a portion at a temperature where the gallium trichloride gas exists as a gas and the gallium monochloride gas solidifies. Therefore, if gallium monochloride gas remains in the second space 212, the gallium monochloride gas is likely to solidify in the generation vessel 200. Therefore, it is possible to prevent the first supply pipe 310 from being clogged due to the gallium monochloride gas entering and solidifying in the first supply pipe 310.

[0057] According to the present embodiment described above, before growing the GaN layer 122, high-temperature cleaning is performed until it is determined that only a predetermined amount of foreign matter is present in the growth vessel 100. This makes it possible to prevent the quality of the GaN layer 122 from deteriorating.

[0058] (1) In this embodiment, the second space 212 is heated so that it has a portion at a temperature at which the gallium trichloride gas solidifies while the gallium monochloride gas exists as a gas when the GaN layer 122 is grown. For this reason, if gallium monochloride gas remains in the second space 212, the gallium monochloride gas tends to solidify in the generation vessel 200. Therefore, it is possible to prevent the first supply pipe 310 from being clogged due to the gallium monochloride gas entering and solidifying in the first supply pipe 310 having a small cross-sectional area.

[0059] Second embodiment A second embodiment will be described. In contrast to the first embodiment, this embodiment is provided with a concentration measuring unit near the outlet 104. As the rest is similar to the first embodiment, a description thereof will be omitted here.

[0060] 2, in the GaN layer manufacturing apparatus of this embodiment, the determination unit 420 is configured to include a concentration measurement unit 424 that measures the concentration of ammonia gas discharged from the exhaust port 104. In addition, the control unit 423 is also connected to the concentration measurement unit 424.

[0061] When the control unit 423 judges an abnormality in the growth vessel 100, the control unit 423 performs the judgment while supplying ammonia gas from the second supply pipe 320 into the growth vessel 100. That is, if a foreign matter containing gallium is attached to the growth vessel 100, the ammonia gas reacts with the foreign matter when the ammonia gas is supplied, and therefore the concentration of the ammonia gas discharged from the exhaust port 104 decreases.

[0062] Therefore, when the measurement result measured by the concentration measuring unit 424 is less than the concentration threshold value, the control unit 423 of this embodiment determines that there is an abnormality in the growth vessel 100. Then, after determining that the growth vessel 100 is in a normal state based on all of the measurement results of the first embodiment and the measurement results measured by the concentration measuring unit 424, the control unit 423 starts the growth of the GaN layer 122.

[0063] According to the present embodiment described above, the ammonia gas concentration is also used to judge an abnormality in the growth vessel 100. Therefore, an abnormality can be judged with higher accuracy.

[0064] (Other embodiments) Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure.

[0065] For example, in each of the above-mentioned embodiments, the configuration of the growth device 10 may be appropriately changed. For example, in each of the above-mentioned embodiments, an example is described in which the rotation displacement mechanism 132 that rotates and displaces the pedestal 120 is provided, but the pedestal 120 may be rotated without being displaced. In addition, the outlet 104 may be disposed on the first lid 102 side of the growth container 100.

[0066] In each of the above embodiments, the second space 212 does not necessarily have to be provided with the partition wall 214.

[0067] Furthermore, in each of the above embodiments, an example has been described in which high-temperature cleaning is performed first while an abnormality determination is performed inside the growth vessel 100. However, high-temperature cleaning may be started after it is determined that the inside of the growth vessel 100 is in an abnormal state. In other words, as long as high-temperature cleaning is performed until it is determined that the inside of the growth vessel 100 is in a normal state, the time point at which it is started may be before an abnormality determination is performed inside the growth vessel 100 or after an abnormality determination is performed inside the growth vessel 100.

[0068] In each of the above embodiments, an example has been described in which an abnormality determination is performed within the growth vessel 100 after the seed substrate 121 is placed on the pedestal 120, but an abnormality determination within the growth vessel 100 may also be performed before the seed substrate 121 is placed on the pedestal 120.

[0069] In addition, in each of the above embodiments, an example has been described in which the control unit 423 adjusts the driving of the heating device 140. However, for example, the control unit 423 may display the measurement results and the determination results on a display device or the like, and an operator may adjust the driving of the heating device 140.

[0070] Furthermore, in each of the above embodiments, an example has been described in which the control unit 423 judges whether there is an abnormality in the growth container 100 based on the intensity of the reflected light Lb when the reflected light Lb is used, but the control unit 423 may also judge whether there is an abnormality in the growth container 100 based on the spots of the reflected light Lb, etc.

[0071] In the first embodiment, the determination unit 420 may include only one of the light receiving unit 421 and the image capturing unit 422. Similarly, in the second embodiment, the determination unit 420 may include only one of the light receiving unit 421 and the image capturing unit 422, in addition to the concentration measurement unit 424. In the second embodiment, the determination unit 420 may be configured not to include the light receiving unit 421 and the image capturing unit 422.

[0072] The control unit and the method described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be implemented by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer. [Explanation of symbols]

[0073] 10 Growth equipment 20 Generator 100 growing containers 101a Hollow part 120 Pedestal 120a one side 121 species substrate 122 GaN layer 140 Heating device 310 Supply piping

Claims

1. A gallium nitride layer manufacturing apparatus for growing a gallium nitride layer (122) on a seed substrate (121) by supplying a gallium-based gas and an ammonia-based gas, comprising: a growth apparatus (10) having a cylindrical growth vessel (100) in which the gallium nitride layer is grown in a hollow portion (101a) constituting a reaction chamber; a pedestal (120) disposed within the hollow portion of the growth chamber, on which the seed substrate on which the gallium nitride layer is grown is disposed; a first supply pipe (310) for supplying a first source gas containing gallium trichloride gas as a gallium-based gas for growing the gallium nitride layer to the growth apparatus; a second supply pipe (320) for supplying a second source gas containing an ammonia-based gas for growing the gallium nitride layer to the growth apparatus; A heating device (140) for heating the inside of the growth vessel; A state determination unit (400) for determining a state inside the growth container, the heating device is adjusted to heat the inside of the growth vessel to a temperature higher than a temperature at which the gallium nitride layer is grown until the state determination unit determines that only less than a predetermined amount of foreign matter is present in the growth vessel, and is adjusted to heat the inside of the growth vessel to a temperature at which the gallium nitride layer is grown when the state determination unit determines that only less than a predetermined amount of foreign matter is present in the growth vessel; a control unit (423) for supplying the first source gas and the second source gas onto the seed substrate to grow the gallium nitride layer after the temperature inside the growth vessel is adjusted by the heating device to a temperature at which the gallium nitride layer is grown.

2. 2. The gallium nitride layer manufacturing apparatus according to claim 1, wherein the state determination unit includes an irradiation unit (410) that irradiates the inside of the growth vessel with irradiation light (La) and determines a state inside the growth vessel based on the irradiation light.

3. 3. The gallium nitride layer manufacturing apparatus according to claim 2, wherein the state determination unit has a light receiving unit (421) that receives reflected light (Lb) of the irradiated light reflected within the growth vessel, and determines a state within the growth vessel based on a component of the reflected light received.

4. The gallium nitride layer manufacturing apparatus of claim 2 or 3, wherein the state determination unit has an imaging unit (422) that images at least one of the irradiated light in the growth vessel and the reflected light (Lb) of the irradiated light reflected within the growth vessel, and determines the state within the growth vessel based on components of the imaged results.

5. the growth vessel is provided with an exhaust port (104) for exhausting unreacted gas of the first source gas and the second source gas; 5. The gallium nitride layer manufacturing device according to claim 1, wherein the state determination unit has a concentration measurement unit (424) for measuring a concentration of the ammonia-based gas in the unreacted gas discharged from the exhaust port, and determines a state inside the growth vessel based on the concentration of the ammonia-based gas.

6. A method for producing a gallium nitride layer, comprising growing a gallium nitride layer (122) on a seed substrate (121) by supplying a gallium-based gas and an ammonia-based gas, the method comprising the steps of: a growth apparatus (10) having a cylindrical growth vessel (100) in which the gallium nitride layer is grown in a hollow portion (101a) constituting a reaction chamber; a pedestal (120) disposed within the hollow portion of the growth chamber, on which the seed substrate on which the gallium nitride layer is grown is disposed; a first supply pipe (310) for supplying a first source gas containing gallium trichloride gas as a gallium-based gas for growing the gallium nitride layer to the growth apparatus; a second supply pipe (320) for supplying a second source gas containing an ammonia-based gas for growing the gallium nitride layer to the growth apparatus; A heating device (140) for heating the inside of the growth vessel; providing a gallium nitride layer manufacturing apparatus including a state determination unit (400) for determining a state inside the growth vessel; heating the inside of the growth vessel to a temperature higher than a temperature at which the gallium nitride layer is grown by the heating device until the state determination unit determines that only foreign matter less than a predetermined amount is present in the growth vessel; adjusting the heating device so that the temperature inside the growth vessel is at a temperature at which the gallium nitride layer is grown after the state determination unit determines that only foreign matter less than a predetermined amount is present inside the growth vessel; supplying the first source gas and the second source gas onto the seed substrate to grow the gallium nitride layer.

Images