WO2007072984A1

WO2007072984A1 - Semiconductor substrate manufacturing method and element structure manufacturing method

Info

Publication number: WO2007072984A1
Application number: PCT/JP2006/325992
Authority: WO
Inventors: Takafumi Yao; Meoung-Whan Cho
Original assignee: Tohoku Techno Arch Co., Ltd.
Priority date: 2005-12-20
Filing date: 2006-12-20
Publication date: 2007-06-28
Also published as: JP4238372B2; JPWO2007072984A1

Abstract

A method for manufacturing a semiconductor substrate relating to a first side plane is provided with a carry-in step of carrying a base substrate into a processing space partitioned from the external space; a chromium layer forming step of forming a chromium layer on the base substrate by vapor deposition; a nitriding step of forming a chromium nitride film by nitriding the chromium layer; and a first crystalline layer growing step of growing a first crystalline layer of a group III nitride semiconductor on the chromium nitride film. The chromium layer forming step and the nitriding step are characterized in that the steps are continuously performed without having the processing space open to the air.

Description

Specification

Manufacturing method of semiconductor substrate and manufacturing method of element structure

The present invention relates to a method for manufacturing a semiconductor substrate and a method for manufacturing an element structure. Background art

In order to obtain a semiconductor substrate, a method of forming an aluminum nitride film by forming an aluminum film on a base substrate by MO CVD and then nitriding the aluminum film in the same furnace has been proposed. (For example, see Patent Document 1). This reduces the impurity contamination of the aluminum nitride film. Patent Document 1: Japanese Patent Application Laid-Open No. 2 00 2-2 8 4 6 0 0 Disclosure of Invention

In the technique disclosed in Patent Document 1, when a group III nitride semiconductor crystal is grown on an aluminum nitride film, a nucleation site is generated due to lattice mismatch between the aluminum nitride film and the group III nitride semiconductor. Easy to be random

The crystallinity of the I I I group nitride semiconductor crystal may be deteriorated.

An object of the present invention is to provide a method for manufacturing a semiconductor substrate and a method for manufacturing an element structure, which can improve the crystallinity of a crystal layer of a group III nitride semiconductor. The method for manufacturing a semiconductor substrate according to the first aspect of the present invention includes a loading step of loading a base substrate into a processing space partitioned from an external space, and a vapor deposition method on the base substrate. A chromium layer forming step of forming a layer; a nitriding step of nitriding the deposit layer to form a chromium nitride layer; and a first crystal layer of a group III nitride semiconductor on the chromium nitride film A first crystal layer growth process for growing the chrome layer, wherein the chromium layer forming process and the nitriding process increase the processing space. It is characterized by being continuously performed without being open.

The method for manufacturing a semiconductor substrate according to the second aspect of the present invention includes a carrying-in process for carrying a base substrate into a processing space partitioned from an external space, and a vapor deposition method on the base substrate. A nitride film forming step for forming a nitride film, and a first crystal layer growing step for growing a first crystal layer of a group III nitride semiconductor on the chromium nitride film, The deposit nitride film forming step and the first crystal layer growing step are performed continuously without opening the processing space to the atmosphere.

The method for manufacturing a semiconductor substrate according to the third aspect of the present invention includes a carrying-in process for carrying a base substrate into a processing space partitioned from an external space, and a vapor deposition method on the base substrate. A nitride layer forming step of forming a layer, a nitriding step of nitriding the deposit layer to form a nitride nitride film having a plurality of triangular pyramid-shaped microcrystal parts, and the chromium A first crystal layer growth step for growing a first crystal layer of a group III nitride semiconductor on the nitride film, wherein the deposition layer forming step and the nitridation step are configured to open the processing space to the atmosphere. It is characterized by being carried out continuously without.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a semiconductor substrate, comprising: a carrying-in step of carrying a base substrate into a processing space partitioned from an external space; and a triangular pyramid on the base substrate by vapor deposition. A chromium nitride film forming step for forming a chromium nitride film having a plurality of microcrystalline portions in shape, and a first crystal for growing a first crystal layer of a group III nitride semiconductor on the chromium nitride film And the first nitride layer growth step and the first crystal layer growth step are performed continuously without opening the processing space to the atmosphere.

The element structure manufacturing method according to the fifth aspect of the present invention includes a preparation step of preparing the second crystal layer as a semiconductor substrate by the semiconductor substrate manufacturing method according to the first to fourth aspects of the present invention; And an element structure forming step of forming an element structure on the semiconductor substrate. Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are given to the same or similar components. Brief Description of Drawings

FIG. 1A is a process cross-sectional view illustrating a method for manufacturing a semiconductor substrate.

FIG. 1B shows a process cross-sectional view illustrating a method for manufacturing a semiconductor substrate.

FIG. 1C is a process cross-sectional view illustrating a method for manufacturing a semiconductor substrate.

FIG. 2A is a process sectional view showing a method for manufacturing a semiconductor substrate.

FIG. 2B shows a process cross-sectional view illustrating a method for manufacturing a semiconductor substrate.

FIG. 2C is a process cross-sectional view illustrating a method for manufacturing a semiconductor substrate.

Figure 3 shows the configuration of the MOCVD system.

Figure 4 shows an SEM photograph of the second crystal layer observed.

Figure 5 shows a SEM photograph of the etched state.

FIG. 6 shows the X-ray diffraction results of the sample obtained in the process shown in FIG. 2C. Figure 7 shows a SEM photograph of the surface of the chromium nitride film.

FIG. 8 shows the X-ray diffraction results of the sample obtained in the process shown in FIG. 1C. FIG. 9 shows a photomicrograph of the surface of the second crystal layer observed.

FIG. 10 shows the X-ray diffraction results of the sample obtained in the step shown in FIG. 2B. Fig. 11 A shows a TEM photograph (comparative example) of the sample cross section.

Fig. 11 B shows a TEM photograph (comparative example) of the sample cross section.

Figure 12 A shows the results of elemental analysis of the sample cross section (comparative example).

Fig. 12 B shows the result of elemental analysis of the sample cross section (comparative example).

Figure 12 C shows the results of elemental analysis of the sample cross section (comparative example).

Figure 1 2D shows the results of elemental analysis of the sample cross section (comparative example).

Figure 13 shows an SEM photograph (comparative example) observing the surface of the chromium nitride film. FIG. 14 shows the X-ray diffraction result (comparative example) of the sample obtained in the process shown in FIG. 1C.

Fig. 15 shows a micrograph (comparative example) of the surface of the second crystal layer observed. Figure 16 shows the results of AFM analysis of the surface of the second crystal layer (comparative example). Fig. 17 shows the X-ray diffraction results (comparative example) of the sample obtained in the process shown in Fig. 2B.

18A shows a process cross-sectional view (variation) showing a method for manufacturing a semiconductor substrate. FIG. 18B shows a process cross-sectional view (modification) showing a method for manufacturing a semiconductor substrate. FIG. 18C shows a semiconductor substrate. 19A shows a process cross-sectional view showing a manufacturing method of the semiconductor substrate (modified example). FIG. 19A shows a process cross-sectional view showing a semiconductor substrate manufacturing method (modified example). FIG. Fig. 19C shows a process cross-sectional view showing a method for manufacturing a semiconductor substrate (modification) Fig. 20 shows an X-ray diffraction result (deformation) of the sample obtained in the process shown in Fig. 1C Example)

FIG. 21 shows the X-ray diffraction result (modified example) of the sample obtained in the process shown in FIG. 2B.

Fig. 22 shows the configuration of the MOHVPE device.

FIG. 23 shows the X-ray diffraction results (modified example) of the sample obtained in the step shown in FIG. 1B and the step shown in FIG. 1C.

Figure 24A shows a cross-sectional SEM photograph (modified example) of the sample obtained in the process shown in Figure 2B. Fig. 24B shows the cross-sectional X-ray diffraction result (modified example) of the sample obtained in the process shown in Fig. 2B.

FIG. 25 shows a cross-sectional TEM photograph (modified example) of the sample obtained in the step shown in FIG. 2B.

FIG. 26 shows a cross-sectional TEM photograph (modified example) of the sample obtained in the process shown in FIG. 19A.

FIG. 27 shows the X-ray diffraction result (modified example) of the sample obtained in the step shown in FIG. 19A.

FIG. 28 shows a block diagram of the MOMB E device.

FIG. 29 shows a cross-sectional SEM photograph and X-ray diffraction result (modified example) of the sample obtained in the process shown in FIG. 2B.

Fig. 3 OA shows the application of the GaN substrate to the device structure.

FIG. 30B shows a diagram showing application of the GaN substrate to the device structure.

FIG. 31 shows a diagram showing an application of the GaN substrate to the device structure.

FIG. 32 is a diagram showing an application of the GaN substrate to the device structure.

FIG. 33 shows a diagram showing application of the GaN substrate to the device structure.

FIG. 34 shows a diagram showing an application of the GaN substrate to the device structure. BEST MODE FOR CARRYING OUT THE INVENTION In the present specification, the “film” may be a continuous film or a discontinuous film. “Film” represents a state formed with a thickness. The present invention relates to a method for forming a chromium layer or a chromium nitride film by vapor deposition. Here, the vapor phase growth method is, for example, MOCVD method, MBE method, MOMBE method, MOHVPE method, HVPE method.

A method for manufacturing a group III nitride semiconductor substrate according to an embodiment of the present invention will be described with reference to FIGS. 1A to 2C are process sectional views showing a method for manufacturing a semiconductor substrate. Figure 3 shows the configuration of device 1 It is. Hereinafter, gallium nitride will be mainly described as an example of a group III nitride semiconductor, but the same applies to other group III nitride semiconductors. In the process shown in FIG. 1A, the base substrate 110 is carried into the MOCVD apparatus 200. That is, base substrate 110 is carried into reaction tube 210 of MOCVD apparatus 200 shown in FIG. 3 and placed on susceptor 216. Then, after the reaction tube 210 is sealed, it is evacuated to ImmTorr. The material of the base substrate 1 10 is, for example, A 1 ₂ 0 ₃ (sapphire), Si, Si C, Ga A s, Zn O, or other semiconductor single crystal, polycrystalline, and amorphous. It can be any substrate of quality, or it can be a single crystal of a metal such as Nb, V, Ta, Zr, Hf, Ti, Al, Cr, Mo, W, Cu, Fe, C It may be a substrate.

In the process shown in FIG. 1B, a chromium layer 115 is formed on the base substrate 110 by MOCVD.

That is, in the MOCVD apparatus 200, as shown in FIG. 3, an organic metal raw material for forming the chromium layer 115 is placed in the raw material tank 201 in the bubbler 220. At least one of N 2, H 2, and Ar flows as a carrier gas into the raw material tank 201 through an MFC (mass flow control trolley) 230. At this time, the MFC 230 controls the flow rate of the carrier gas. The organometallic raw material vaporized in the raw material tank 201 flows into the reaction tube 210 through the EPC (Electrocon ssureconcentro1 1 er) 240 together with the carrier gas. At this time, EPC 240 controls the flow rate of the carrier gas and the vaporized organometallic raw material. In the reaction tube 2 10, the heater 214 heats the base substrate 110 through the susceptor 216 to keep the base substrate 110 at a constant temperature. Then, when the vaporized organometallic raw material is supplied to the vicinity of the base substrate 110, the chromium layer 115 is formed on the base substrate 110 by vapor deposition.

The organic metal raw material for forming the chromium layer 1 1 5 is (CH ₃ C ₅ H ₄ ) ₂ Cr is preferred. (CH ₃ C ₅ H ₄ ) ₂ Cr has a lower melting point than other Cr organometallic raw materials (approximately 35 ° C), making it easier to control the pressure in the gaseous state. The organometallic raw material for forming the chromium layer 1 1 5 may be (C ₆ H ₆ ) ₂ Cr, (C ₂ H ₅ ) ₂ Cr, or the like.

Further, in the raw material tank 201, a metal compound raw material may be put in place of the organic metal raw material. Examples of the metal compound raw material include Cr (C ₅ H ₇ 0 ₂ ) 3, Cr (CnH ^ O ^ ₃ ), and Cr (C ₅ HF ₆ O ₂ ) ₃ .

Here, the chromium layer 1 15 is formed because the lattice constant of chromium nitride formed by nitriding is close to that of gallium nitride, and the lattice mismatch with gallium nitride is small.

In the step shown in FIG. 1C, the chromium layer 1 15 is nitrided to form a chromium nitride film 120.

That is, in the MOCVD apparatus 200, as shown in FIG. 3, hydrogen gas or nitrogen gas (hereinafter referred to as nitriding gas) containing ammonia (NH ₃ ) gas is supplied to the vicinity of the chromium layer 1 15 in the reaction tube 210. Is done. Here, the heater 2 14 applies force to the base substrate 1 10 via the susceptor 2 16 [1 heat, and the temperature of the base substrate 1 10 (nitriding temperature of the chromium layer 1 15) is maintained at 600 ° C. or higher. As a result, the chromium layer 1 15 is nitrided to form the chromium nitride film 120.

Here, the nitriding temperature of the chromium layer 115 is preferably 1000 ° C. or higher (1273 K or higher), more preferably 1040 ° C. or higher, and further preferably 1060 ° C. or higher. The chromium nitride film 120 functions as a buffer layer that relieves stress between the base substrate 110 and a first crystal layer 130 and a second crystal layer 140 described later. The chromium nitride film 120 functions as a seed film for crystal growth of a first crystal layer 130 described later. Further, the chromium nitride film 120 functions as a peeling layer in an etching process described later. In this process, when the surface of the sample obtained by nitriding the substrate substrate 110 at a heating temperature of 100 ° C. or higher is observed with a microscope, for example, an SEM photograph shown in FIG. 7 is obtained. As shown in FIG. 7, the chromium layer 115 is almost entirely nitrided to form a chromium nitride film 120 having a plurality of triangular pyramid-shaped convex portions (microcrystalline portions) on the surface.

Also, the steps shown in FIGS. 1A to 1C are performed without opening the reaction tube 210 of the MOCVD apparatus 200 to the atmosphere (in n−s i t u). As a result, when the heating temperature of the base substrate 1 10 is 1000 ° C. or higher, a convex portion (slightly on the surface of the chromium nitride film 120 with the nitriding gas uniformly supplied to the chromium layer 1 15 Crystal part) is formed. For this reason, the size of the convex portion (microcrystalline portion) on the surface of the chromium nitride film 120 becomes uniform (see the SEM photograph in FIG. 7). As a result, in the process shown in FIG. 2A, which will be described later, the nucleation size for the first crystal layer 130 to crystallize is uniformly distributed, so that the crystallinity of the first crystal layer 130 is improved. be able to. Therefore, the crystal layer of the second crystal layer 140 grown on the first crystal layer 130 can be improved in the step shown in FIG. 2B described later.

Further, when an X-ray analysis is performed on the chromium nitride film 120, an X-ray diffraction result shown in FIG. 8 is obtained. As shown in FIG. 8, the peak half-value width of the (1 1 1) plane of the chromium nitride film 120 is 1 310 [a r c s e c]. This shows that the crystallinity of the chromium nitride film 120 is good. In the step shown in FIG. 2A, a first crystal layer 130 of a group I I I nitride semiconductor is grown on the chromium nitride film 120 by MOCVD.

That is, in the MOC VD apparatus 20 °, as shown in FIG. 3, the organometallic raw material for forming the first crystal layer 130 is put in the raw material tank 201 in the bubbler 220. At least one of N2, H2, and Ar flows as carrier gas into the raw material tank 201 via the MFC 230. At this time, the M FC 230 controls the flow rate of the carrier gas. Vaporization in the material tank 201 The organometallic raw material flows into the reaction tube 210 through the EPC 240 together with the carrier gas. At this time, the EPC 240 controls the flow rate of the carrier gas and the vaporized organometallic raw material. Further, nitriding gas flows into the reaction tube 210. In the reaction tube 210, the heater 214 heats the base substrate 110 through the susceptor 216 to keep the base substrate 110 at about 600 to 1000 ° C. Then, the vaporized organometallic raw material and the nitriding gas are supplied in the vicinity of the chromium nitride film 120, so that the first crystal layer 130 is formed by vapor growth on the chromium nitride film 120. Be filmed. As a result, the multilayer ML 1 including the chromium nitride film 120 and the first crystal layer 130 is formed on the base substrate 110. The organometallic raw material for forming the first crystal layer 130 is, for example, trimethylgallium (TMG). The first crystal layer 130 can be composed of, for example, a GaN single crystal, a polycrystal, or an amorphous body. The thickness of the first crystal layer 130 is preferably several tens of A to several tens of μπι. The growth temperature of the first crystal layer 130 is preferably around 900 ° C. The pressure in the reaction tube 2 10 is maintained at 500 Torr, for example. The flow rate of the organic metal raw material is, for example, 300 cc. The flow rate of the hydrogen gas contained in the nitriding gas is, for example, 10 liters Z.

In the step shown in FIG. 2B, the second crystal layer 140 of the I II nitride semiconductor is grown on the first crystal layer 130 at a temperature higher than the growth temperature of the first crystal layer 130 by MOCVD.

That is, in the MOCVD apparatus 200, the heater 2 14 heats the base substrate 110 via the susceptor 216 and keeps the base substrate 110 at about 1100 openings. The growth temperature of the second crystal layer 140 is equal to the growth temperature of the first crystal layer 130 (

The temperature is about 1 100 ° C, which is higher than around 900 ° C. Here, the second crystal layer 14 ° is a single crystal of G a N. The film thickness of the second crystal layer 140 is

10 Ομπ! ~ 50 les, preferably to be Ομπι. The other points are the same as those shown in Fig. 2 (b). When SEM observation is performed on the cross section of the sample obtained in this process, for example, the result shown in the SEM photograph in FIG. 4 is obtained. As shown in FIG. 4, no cracks due to dislocations are observed in the second crystal layer 140 within the field of view observed by SEM. This confirms that the crystallinity of the second crystal layer 140 is good.

Further, the steps shown in FIGS. 1A to 2B are continuously performed without releasing the atmosphere in the reaction tube 2 10 of the MOCVD apparatus 200 (in n−s i tu). As a result, the crystallinity of the second crystal layer 140 is maintained in a good state, and almost no pitch is formed on the surface (see FIG. 9).

Further, when an X-ray analysis is performed on the second crystal layer 140, the X-ray diffraction result shown in FIG. 10 is obtained. As shown in FIG. 10, the peak half-value width of the (0002) plane of the second crystal layer 140 is 467 [ar c s e c]. This shows that the crystallinity of the second crystal layer 140 is good.

In the step shown in FIG. 2C, the chromium nitride film 120 is selectively etched using a chemical solution. In other words, the chromium nitride film 120 is wet etched from the side.

Here, Etsuchanto (chemical solution), for example, a mixed aqueous solution of nitrate 2 cerium ammonium Niu arm perchlorate (HC 1_Rei _{_{4) (C e (ΝΉ 4}} ) 2 (ΝΟ 3) 6) are preferred However, it is not limited to this.

The etching rate can be adjusted according to the temperature and concentration of the chemical solution. By adjusting the etching rate, cracks that occur when the first crystal layer 130 and the second crystal layer 140 are separated from the base substrate 110 can be suppressed.

If the cross section (etched state) of the sample is observed by SEM during this process, for example, the result shown in the SEM image of FIG. 5 is obtained. As shown in FIG. 5, in the chromium nitride film 120 between the base substrate 1 10 and the first crystal layer 1 30, the etched portion 120 a is replaced with the unetched portion 1. Located on the side of 20b. The etched portion 120a is a hollow portion.

When the chromium nitride film 120 is etched, the first crystal layer 130 and the second crystal layer 140 are separated from the base substrate 110 as shown in FIG. 2C. That is, the first crystal layer 130 and the second crystal layer 140 are self-supported from the base substrate 110 to manufacture a GaN substrate (template substrate) SB.

Figure 6 shows the X-ray diffraction results of the sample obtained in this process. In FIG. 6, the diffraction profile of the (0002) plane of the sample obtained in this step is shown by a solid line, and the diffraction profile of the (0002) plane of the sample obtained in the previous step (step shown in FIG. 2B) is It is shown with a broken line for comparison. As shown in Fig. 6, the peak half-value width of (0002) plane before this process (broken line) is 2 4 1 [arcsec], and after performing this process (solid line) of (0002) plane The peak half-width is 229 [arcsec]. As a result, it can be seen that the etching was performed while the crystallinity of the second crystal layer 140 was kept good.

(Comparative example)

Consider a case where the reaction tube 210 of the MOC VD apparatus 200 is opened to the atmosphere between the process shown in FIG. 1B and the process shown in FIG. 1C.

When the sample obtained by the process shown in Fig. 1B is exposed to the atmosphere, the results shown in the TEM photographs of Figs. 11A and 11B and the elemental analysis maps of Figs. 12A to 12D are obtained. That is, a surface oxide film 1 1 6 j is formed on the chromium layer 1 1 5 j (see FIGS. 11A and 11B). In addition, in the elemental analysis maps shown in Fig. 12A to Fig. 12D, the nitrogen map (see Fig. 12B), the chromium map (see Fig. 12C), and the oxygen map (see Fig. 12D) are compared. It can be seen that layer 1 1 5 j is partially hatched and subjected to oxygen contamination. Accordingly, in the process shown in FIG. 1C, when the heating temperature of the base substrate 1 10 is 1 000 ° C. or higher, the nitriding gas is inhomogeneous in the chromium layer 1 15 j. In the supplied state, convex portions (microcrystalline portions) are formed on the surface of the chromium nitride film. As a result, the size of the convex portion (microcrystalline portion) in the comparative example is less than that in the case where the air is not released between the process shown in FIG. 1B and the process shown in FIG. 1C (see FIG. 7). It becomes uniform (see SEM picture in Fig. 13).

In the elemental analysis maps shown in FIGS. 12A to 12D, the photograph shown in FIG. 12A is a TEM photograph similar to that shown in FIG. 11A.

Furthermore, when X-ray analysis is performed on the chromium nitride film 120, the X-ray diffraction results shown in FIG. 14 are obtained. As shown in FIG. 14, the peak half-value width of the (1 1 1) plane of the chromium nitride film is 2847 [ar c s e c]. As a result, the chromium nitride film according to the comparative example has poor crystallinity as compared to the case where the atmosphere is not released between the process shown in FIG. 1B and the process shown in FIG. 1C (see FIG. 8). I understand that

Next, consider the case where the inside of the reaction tube 210 of the MOCVD apparatus 200 is opened to the atmosphere between the process shown in FIG. 1C and the process shown in FIG. 2A. When the sample obtained by the process shown in Fig. 1C is exposed to the atmosphere, the surface of the chromium nitride film is oxidized. As a result, the crystallinity of the second crystal layer deteriorates, and pits are formed on the surface (see FIGS. 15 and 16). FIG. 16 shows the result of AFM analysis of the surface of the second crystal layer.

Furthermore, when X-ray analysis is performed on the second crystal layer, the X-ray diffraction results shown in Fig. 17 are obtained. As shown in Fig. 17, the peak half-value width of the (0002) plane of the second crystal layer is 55 7 [a r c s e c]. As a result, the crystallinity of the second crystal layer is worse than when the atmosphere is not released between the process shown in FIG. 1C and the process shown in FIG. 2A (see FIG. 10). I understand.

(Modification)

Moreover, when the process shown in FIG. 1B to FIG. 2A is continuously repeated without opening to the atmosphere, a plurality of multilayers ML 1 to ML 4 are formed on the base substrate 1 10 as shown in FIG. 18A. Is done. This allows multiple multilayers ML 1 to ML 4 to be stacked The formed structure 1 0 0 is formed on the base substrate 1 1 0.

In this structure 1 0 0, the chromium nitride layer 1 2 0 and the first crystal layer 1 3 0 are alternately stacked, so that the structure between the base substrate 1 1 0 and the second crystal layer 1 4 0 The working internal stress can be relaxed.

1B to 2A may be performed in the same apparatus or may be performed in different apparatuses. When performed in different devices, the reaction chambers are connected by a mechanism that can be transported without being exposed to the atmosphere (for example, a transport path).

In the step shown in FIG. 18B, a plurality of chromium nitride layers 120 are selectively etched simultaneously using a chemical solution. That is, as shown in FIG. 18B, each of the plurality of chromium nitride layers 120 is etched from the side. Here, the etching progresses while the crystal layer 1 30 is destroyed as the etching of the chromium nitride layer 1 2 0 in each of the multiple layers M L 1 to M L 4 progresses. As a result, a plurality of paths through which the chemical solution permeates are formed, and these paths are coupled to each other, so that the path area for the chemical solution to permeate increases. For this reason, the etching rate can be improved. In addition, since the multiple multilayers ML 1 to ML 4 relax the internal stress acting between the base substrate 110 and the second crystal layer 140 during the etching, the internal stress of the second crystal layer 140 Can be maintained in a substantially uniform state.

As the etchant (chemical solution), for example, a mixed water solution of perchloric acid (HC 1 0 ₄ ) and 2 cerium ammonium nitrate (C e (NH ₄ ) ₂ (N 0 ₃ ) ₆ ) is suitable. Yes, but not limited to this.

When the plurality of chromium nitride layers 1 2 0 are etched, as shown in FIG. 18 C, the second crystal layer 1 4 0 and the adjacent first crystal layer 1 3 0 are separated from the base substrate 1 1 0. To do. That is, the second crystal layer 140 and the adjacent first crystal layer 130 are made independent from the base substrate 110 to manufacture the GaN substrate SB. The At this time, in the second crystal layer 140, the internal stress is in a substantially uniform state. As a result, the risk of cracking in the second crystal layer 140 is reduced.

Here, the first crystal layer 130 adjacent to the second crystal layer 140 is not etched by the etchant (chemical solution) and becomes a part of the GaN substrate SB. 2 The process of separating the second crystal layer 140 and the first crystal layer 1 30 adjacent thereto from the base substrate 110 by repeating the process shown in 2A continuously without exposing to the atmosphere is stable and short. Can be done in time.

Further, instead of the process shown in FIG. 1B and the process shown in FIG. 1C, the process shown in FIG. 19A may be performed. In the process shown in FIG. 19A, a chromium nitride film 120 i is formed directly on the base substrate 110 by the MOCVD method. That is, in the MOC VD apparatus 200, as shown in FIG. 3, the organic metal raw material for forming the chromium layer 1 15 (FIG. 1B) is put in the raw material tank 201 in the bubbler 220. At least one of N2, H2, and _Ar flows as carrier gas into the raw material tank 201 via the MFC 230. At this time, the MFC 230 controls the flow rate of the carrier gas. The organometallic raw material vaporized in the raw material tank 201 flows into the reaction tube 210 through the EPC 240 together with the carrier gas. At this time, the EPC 240 controls the flow rate of the carrier gas and the vaporized organometallic raw material. In addition, nitriding gas flows into the reaction tube 210. Within the reaction tube 210, the heater 214 heats the base substrate 110 through the susceptor 216 to keep the base substrate 110 at a constant temperature. Then, the vaporized organometallic raw material and the nitriding gas are supplied to the vicinity of the base substrate 110, whereby the chromium nitride film 120 i is formed on the base substrate 110 by vapor phase growth.

Note that the growth temperature of the chromium nitride film 120 i is maintained at 600 ° C or higher. The The growth temperature of the chromium nitride film 120 i is preferably 1000 ° C or higher (1 273 K or higher), more preferably 1040 ° C or higher, and more preferably 1060 ° C or higher. preferable.

When the X-ray analysis is performed on the chromium nitride film 120 i in the sample obtained in this step, the X-ray diffraction result shown in FIG. 20 is obtained. As shown in FIG. 20, the peak half-value width of the (1 1 1) plane of the chromium nitride film 120 i is 97 1 [a r c s e c]. This shows that the crystallinity of the chromium nitride film 120 i is better than the crystallinity of the chromium nitride film according to the comparative example (see FIG. 14).

Further, when the X-ray analysis is performed on the second crystal layer 140 i of the sample that has been subjected to the process shown in FIG. 19B and the process shown in FIG. 19C, the X-ray diffraction result shown in FIG. 21 is obtained. As shown in FIG. 21, the peak half-value width of the (0002) plane of the second crystal layer 140 i is 332 [a r c s e c]. Thus, it can be seen that the crystallinity of the second crystal layer 140 i is better than that of the chromium nitride film according to the comparative example (see FIG. 17).

Further, at least one of the steps shown in FIGS. 1A to 2B may be performed in the reaction tube 310 of the MOHVPE apparatus 300. FIG. 22 is a configuration diagram of the M OHVPE apparatus 300. At this time, the MOCVD apparatus 200 shown in FIG. 3 and the MOHVPE apparatus 300 shown in FIG. 22 are connected via the transfer space 40 (see FIG. 29). The transfer space 40 is in a vacuum state or a state filled with an inert gas. An opening / closing mechanism is provided between the MQCVD apparatus 200 or the MOH VPE apparatus 300 and the transfer space 40, which is closed during processing and opened during transfer. Thereby, the process shown in FIGS. 1A to 2B can be continuously performed without opening to the atmosphere.

For example, in the process shown in FIG. 1A, the base substrate 110 is carried into the MOHVPE apparatus 300. That is, the base substrate 110 is carried into the reaction tube 310 of the MOHV PE apparatus 300 shown in FIG. 22 and placed on the susceptor 316. The The inside of the reaction tube 310 is evacuated to 1 mm Torr after being sealed.

For example, in the process shown in FIG. 1B, a chromium layer 115 is formed on the base substrate 110 by the MOHVPE method.

That is, in the MOHVPE apparatus 300, as shown in FIG. 22, the organic metal raw material for forming the chromium layer 115 is placed in the raw material tank 301 in the bubbler 320. At least one of N2, H2, and Ar flows as carrier gas into the raw material tank 301 via the MFC 330. At this time, the MFC 330 controls the flow rate of the carrier gas. The organometallic raw material vaporized in the raw material tank 301 flows into the reaction tube 310 through the EPC 340 together with the carrier gas. At this time, the EPC 340 controls the flow rate of the carrier gas and the vaporized organometallic raw material. In the reaction tube 310, the heater 3 14 heats the base substrate 110 through the gas in the reaction tube 310 to keep the base substrate 110 at a constant temperature. Then, the vaporized organometallic raw material is supplied to the vicinity of the base substrate 1 10, whereby the chromium layer 1 15 is formed on the base substrate 1 10 by vapor phase growth.

An organic metal raw material for forming the chromium layer 1 15 is, for example, (CH ₃ C ₅ H ₄ ) ₂ Cr. The flow rate of the vaporized organometallic raw material is preferably 0.9 sccm, and the flow rate of the carrier gas (for example, H ₂ ) is preferably 3250 sccm. The temperature of the base substrate 110 is preferably from room temperature to 1100 ° C. The film thickness of the chromium layer 115 is preferably several tens of A to several tens of μπι.

For example, in the step shown in FIG. 1C, the chromium layer 115 is nitrided to form the chromium nitride film 120.

That is, in the MOHVP dredge apparatus 300, as shown in FIG. 22, hydrogen gas or nitrogen gas (hereinafter referred to as nitriding gas) containing ammonia (モ₃ ) gas is supplied in the vicinity of the chromium layer 115 in the reaction tube 310. Is done. here, 1 1

The heater 314 heats the lower substrate 110 via the gas in the reaction tube 310, and the temperature of the base substrate 110 (nitriding temperature of the chromium layer 115) is maintained at 600 ° C or higher. As a result, the chromium layer 1 1 5 is nitrided and the chromium nitride film 1 1

20 is formed.

In addition to the nitriding gas, hydrogen gas or nitrogen gas (hereinafter referred to as a reducing gas) containing hydrogen chloride (HC 1) gas may be further supplied into the reaction tube 310.

Here, using the MOHVP E apparatus 300, X-ray analysis was performed on the samples obtained in the process shown in FIG. 1B and the process shown in FIG. 1C, respectively, and (a) in FIG. 23 and (b) in FIG. The X-ray diffraction results shown in Fig. 1 were obtained. By comparing (a) in FIG. 23 and (b) in FIG. 23, it can be seen that the chromium layer 115 is changed to the chromium nitride film 120 by the nitriding treatment. The nitride nitride film 120 has a body-centered cubic structure (BCC: BodeyCenterCuBic).

For example, in the process shown in FIG. 2A, a first crystal layer 130 of an I II nitride semiconductor is grown on the chromium nitride film 120 by MOHVPE. That is, in the MOHVPE apparatus 300, as shown in FIG. 22, the heater 315 heats the Ga source 322 via the gas in the reaction tube 310, and vaporized gallium is generated. Also, nitriding gas flows into the reaction tube 310. In the reaction tube 3 10, the heater 314 heats the base substrate 110 through the gas in the reaction tube 310 to keep the base substrate 110 at about 600 to 1000 ° C. Then, the vaporized gallium and the nitriding gas are supplied in the vicinity of the chromium nitride film 120, whereby the first crystal layer 130 is formed on the chromium nitride film 120 by vapor phase growth. . As a result, a multilayer ML 1 including the chromium nitride film 120 and the first crystal layer 130 is formed on the base substrate 110.

For example, in the process shown in FIG. 2B, the first crystal layer 1 is formed by the MOHVPE method.

On top of 30, the first crystal layer 1 Group III nitride at a temperature higher than the growth temperature of 30 A second crystalline layer 140 of a physical semiconductor is grown.

That is, in the MOHVPE apparatus 300, the heater 314 heats the base substrate 110 via the gas in the reaction tube 310 and keeps the base substrate 110 at about 110 ° C. The growth temperature of the second crystal layer 140 is about 1100 ° C., which is higher than the growth temperature (around 900 ° C.) of the first crystal layer 130. Here, the second crystal layer 140 is a GaN single crystal. The film thickness of the second crystal layer 140 is 10 Ομπ! It is preferably ~ 50 〜μπι. The other points are the same as those shown in FIG. 2A.

When the cross section of the sample obtained in this step is observed by SEM, for example, the result shown in the SEM photograph of FIG. 24A is obtained. As shown in FIG. 24A, no cracks due to dislocations or the like are observed in the second crystal layer 140 within the field of view observed by SEM. In addition, when the cross section of the sample obtained in this step is observed by TEM, the results shown in FIG. 25 are obtained. As shown in Fig. 25, no dislocation loop or the like is observed in the field of view observed by TEM. This confirms that the crystallinity of the second crystal layer 140 is good.

Further, when X-ray analysis is performed on the second crystal layer 140, the X-ray diffraction result shown in FIG. 24B is obtained. As shown in FIG. 24B, the peak half-value width of the (0002) plane of the second crystal layer 140 is 491 [ar c s e c]. The peak half-value width of the (1 0— 1 1) plane of the second crystal layer 140 is 341 [a r c s e c]. This shows that the crystallinity of the second crystal layer 140 is good.

Note that the optimum nitriding conditions vary depending on the film thickness of the glom layer 1 15 (see Fig. 1B). The second crystal layer 140 was grown at a growth temperature of 1 000 ° C. or more while changing the ratio of nitriding gas and reducing gas to 10-40. Alternatively, instead of the steps shown in FIGS. 1B and 1C, the step shown in FIG. 19A may be performed in the reaction tube 310 of the MOHVP E device 300.

That is, in the MOHVP E device 300, as shown in FIG. Layer 1 1 5. Organometallic raw material for forming (Fig. IB) is placed in the raw material tank 301 in the bubbler 320. At least one of N 2, H 2, and Ar flows as a carrier gas into the raw material tank 301 via the MFC 330. At this time, the MFC 330 controls the flow rate of the carrier gas. The organometallic raw material vaporized in the raw material tank 30 1 flows into the reaction tube 3 10 through the EPC 340 together with the carrier gas. At this time, the EPC 340 controls the flow rates of the carrier gas and the vaporized organometallic raw material. Also, nitriding gas flows into the reaction tube 310. In the reaction tube 310, the heater 314 heats the base substrate 110 through the gas in the reaction tube 310 to keep the base substrate 110 at a constant temperature. Then, the vaporized organometallic raw material and the nitriding gas are supplied to the vicinity of the base substrate 110, whereby the chromium nitride film 120 i is formed on the base substrate 110 by vapor phase growth.

When the cross section of the sample obtained in this process is observed by TEM, the results shown in Fig. 26 are obtained. As shown in the TEM image (see Fig. 26a) and its magnified image (see Fig. 26c), dislocation loops etc. are not observed in the field of view observed by TEM. The electron diffraction results (see b in Fig. 26) also show diffraction spots distributed almost symmetrically. This confirms that the crystallinity of the second crystal layer 140 is good.

When the X-ray analysis is performed on the chromium nitride film 120 i of the sample obtained in this step, the X-ray diffraction result shown in FIG. 27 is obtained. As shown in FIG. 27, the peak of the (1 1 1) plane of the chromium nitride film 120 i is strong, and it can be seen that the chromium nitride film 120 i is (1 1 1) oriented. .

Further, at least one of the steps shown in FIGS. 1A to 2B may be performed in the reaction tube 410 of the MOMBE apparatus 400. FIG. 28 shows the same configuration of the MO MBE device 400. At this time, the MOCVD apparatus 200 shown in FIG. 3, the MOHVPE apparatus 300 shown in FIG. 22, and the MOMBE apparatus 400 shown in FIG. 28 are connected via the transfer space 40 (see FIG. 29). Carrying The sending space 40 is in a vacuum state or a state filled with an inert gas. Between the MOCVD apparatus 200, the MOHVPE apparatus 300 or the MOMBE apparatus 400 and the transfer space 40, an opening / closing mechanism that is closed during processing and opened during transfer is provided. Thereby, the process shown in FIGS. 1A to 2B can be continuously performed without opening to the atmosphere.

For example, in the process shown in FIG. 1A, the base substrate 110 is carried into the MOMBE apparatus 400. That is, the base substrate 110 is carried into the reaction tube 4 10 of the MOMBE apparatus 400 shown in FIG. 28 and placed on the susceptor 4 16. The inside of the reaction tube 410 is sealed and then evacuated to ImmTorr.

For example, in the process shown in FIG. 1B, a chromium layer 1 15 is formed on the base substrate 1 10 by MOMBE.

That is, in the MOMBE apparatus 400, as shown in FIG. 28, the organometallic raw material for forming the chromium layer 1 15 is put in the raw material tank 401 in the bubbler 420. At least one of N2, H2, and Ar flows as carrier gas into the raw material tank 401 via the MFC 430. At this time, the M FC430 controls the flow rate of the carrier gas. The organometallic raw material vaporized in the raw material tank 401 flows into the reaction tube 410 through the EPC 440 together with the carrier gas. At this time, the EPC 440 controls the flow rate of the carrier gas and the vaporized organometallic raw material. In the reaction tube 410, the heater 414 heats the base substrate 110 through the gas in the reaction tube 410 to keep the base substrate 110 at a constant temperature. Then, when the vaporized organometallic raw material is supplied to the vicinity of the base substrate 110, a chromium layer 115 is formed on the base substrate 110 by vapor phase growth.

That is, in the MOMB E device 400, as shown in FIG. Hydrogen gas containing nitrogen (NH ₃ ) gas or nitrogen gas (hereinafter referred to as nitriding gas) force Supplied in the vicinity of the chromium layer 1 15 in the reaction tube 410. Here, the heater 4 14 heats the base substrate 1 10 through the gas in the reaction tube 4 10, and the temperature of the base substrate 1 10 (the nitriding temperature of the chromium layer 1 15) is 600 ° C or higher. Retained. As a result, the chromium layer 1 15 is nitrided to form the chromium nitride film 120.

In addition to the nitriding gas, hydrogen gas or nitrogen gas (hereinafter referred to as a reducing gas) containing hydrogen chloride (HC 1) gas may be further supplied into the reaction tube 410.

For example, in the step shown in FIG. 2A, the first crystal layer 130 of the group II nitride semiconductor is grown on the chromium nitride film 120 by the MOMBE method. That is, in the MOMBE apparatus 400, as shown in FIG. 28, an organometallic raw material for forming the first crystal layer 130 is put in a raw material tank 401 in the bubbler 420. At least one of N 2, H 2, and Ar flows into the raw material tank 401 through the MFC 430 as a carrier gas. At this time, the MFC 430 controls the carrier gas flow rate. The organometallic raw material vaporized in the raw material tank 401 flows into the reaction tube 410 through the EPC 440 together with the carrier gas. At this time, the EPC 440 controls the flow rate of the carrier gas and the vaporized organometallic raw material. Also, nitriding gas flows into the reaction tube 410. In the reaction tube 4 10, the heater 414 heats the base substrate 110 through the susceptor 416 to keep the base substrate 110 at about 600 to 1000 ports. Then, the vaporized organometallic raw material and the nitriding gas are supplied in the vicinity of the chromium nitride film 120, whereby the first crystal layer 130 is formed by vapor phase growth on the chromium nitride film 120. . As a result, the multilayer ML 1 including the chromium nitride film 120 and the first crystal layer 130 is formed on the base substrate 110. For example, in the step shown in FIG. 2B, a group III nitride is formed on the first crystal layer 130 by a MOMBE method at a temperature higher than the growth temperature of the first crystal layer 130. A second crystalline layer 140 of semiconductor is grown.

That is, in the MOMBE apparatus 400, the heater 414 heats the base substrate 110 via the gas in the reaction tube 4 10 to keep the base substrate 110 at about 1100 ° C. The growth temperature of the second crystal layer 140 is about 1100 ° C., which is higher than the growth temperature of the first crystal layer 130 (around 900 ° C.). Here, the second crystal layer 140 is a GaN single crystal. The film thickness of the second crystal layer 140 is 10 Ομπ! It is preferably ~ 50 〜μπι. The other points are the same as the process shown in Fig. 2 (b).

The MOMBE device 400 may be equipped with, for example, a reflection high-energy electron diffraction (RHEED) gun 414 and a RHEED screen 4 16. You may be able to observe the transmission diffraction pattern at the. The susceptor 416 that holds the base substrate 1 10 may be attached to the tip of the operation unit (Manipu lar) 41 8.

1A to 2B may be performed by any vapor phase growth method including CVD, MOCVD, MBE, MOMBE, MOHVPE, and HVPE.

For example, the steps shown in FIGS. 1A to 2B may be performed using the multi-chamber system 1 shown in FIG. The multi-chamber system 1 includes a MO CVD apparatus 200, a MOHVPE apparatus 300, a MOMBE apparatus 400, a CVD apparatus 10, an MBE apparatus 20, an HVPE apparatus 30, and a transfer space 40. The MOCVD apparatus 200, the MOHVPE apparatus 300, the MOMBE apparatus 400, the CVD apparatus 10, the MBE apparatus 20, and the HVPE apparatus 30 are connected to each other through a transfer space 40. The transfer space 40 is in a vacuum state or filled with an inert gas. MOCVD equipment 200, MOHVPE equipment 300, MOMBE equipment 400, CVD equipment 10, MB Between the E device 2.0 and the HVPE device 30 and the transfer space 40, an opening / closing mechanism that is closed during processing and opened during transfer is provided. Thereby, the process shown to FIG. 1A-FIG. 2B can be performed continuously, without releasing to air | atmosphere. For example, using the multi-chamber system 1, the process shown in FIGS. 1A to 1C is performed by the MOC VD method, and the sample is transferred from the MOC VD apparatus 200 to the HVPE apparatus 30 via the transfer space 40. The process shown in FIGS. 2A and 2B may be performed by the HVPE method.

When the cross section of the sample obtained in this way is observed by SEM, for example, the result shown in the SEM photograph of OA in Fig. 3 is obtained. As shown in FIG. 3 OA, no cracks due to dislocations or the like are observed in the second crystal layer 140 within the field of view observed by SEM. This confirms that the crystallinity of the second crystal layer 140 is good.

Further, when X-ray analysis is performed on the second crystal layer 140, the X-ray diffraction result shown in FIG. 30B is obtained. As shown in FIG. 30B, the peak half-value width of the (000 2) plane of the second crystal layer 140 is 34 3 [a r c s e c]. The peak half-value width of the (1 0— 1 1) plane of the second crystal layer 140 is 3 7 5 [ar c s e c]. This shows that the crystallinity of the second crystal layer 140 is good.

(Application to device structure of G a N substrate)

The G a N substrate SB obtained as described above is applied to a G a N-based light emitting device (eg, In G a N / G a N blue light emitting diode, G a N / A 1 G a N ultraviolet light emitting diode, and so on). Laser diodes), GaN-based electronic elements, etc. For example, an element structure as shown below can be formed.

As shown in Fig. 31, the 11-0 & 1 ^ layer 640 is formed on the GaN substrate SB. Next, an active layer (InGaN / GaN quantum well structure) 650 is formed on the n_GaN layer 640. Then, a p_G a N layer (or n—A 1 G a N layer) 6 60 is formed on the active layer 650. This allows you to An element structure 600 having a n-type electrode can be formed. As a result, it is possible to avoid the loss of the light emitting area due to the electrodes, and to efficiently dissipate the heat generated from the active layer, which can be expected to improve the element operating characteristics.

As shown in FIG. 32, an n_Ga N layer (or n—A 1 GaN layer) 722 is formed on a GaN substrate SB. Next, an active layer (InGaN-no-GaN quantum well structure) 724 is formed on the n_GaN layer 722. Then, a p-GaN layer (or p-AlGaN layer) 726 is formed on the active layer. Further, an upper electrode 724 and a lower electrode 722 are formed. As a result, a light emitting device structure 700 having a top-down electrode can be formed. As a result, it is possible to avoid the loss of the light emitting area due to the electrodes, and to efficiently dissipate the heat generated from the active layer, which can be expected to improve the element operating characteristics.

As shown in FIG. 33, the i—G a N layer 821 is formed on the G a N substrate S B. Next, an n-GaN layer 822 is formed on the i-type GaN layer 821. An n—A 1 GaN layer 840 is formed on the η—Ga N layer 822. Then, a part of the n—A 1 Ga N layer 840 is etched to form a source electrode 832 and a drain electrode 838. Thereafter, a gate electrode 834 is formed on the n—A 1 GaN layer 840. As a result, a GaN-based heterojunction electronic device structure 800 having a top-down electrode can be formed.

As shown in FIG. 34, an n—GaN layer 930 is formed on the GaN substrate SB. Next, a 1-03 layer (or i-A 1 GaN layer) 940 is formed on the 11-0 & layer 930. Then, source electrodes 912 and 914 and a gate electrode 916 are formed on the i-G a N layer 940. Thereafter, a drain electrode 918 is formed on the back surface of the GaN substrate SB. Thereby, the vertical electronic element structure 900 can be formed.

As described above, according to the present invention, the crystallinity of the GaN substrate SB is greatly improved. Therefore, the crystallinity of each layer included in the device structure formed on it Can greatly improve device characteristics and yield. The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

Claims

1. a carry-in process for carrying the base substrate into the processing space partitioned from the external space;

A chromium layer forming step of forming a chromium layer on the base substrate by vapor deposition;

0a.Blue

A nitriding step of nitriding the chromium layer to form a chromium nitride film; a first crystal layer growing step of growing a first crystal layer of an I II nitride semiconductor on the chromium nitride film;

With

Surrounding

The chromium layer forming step and the nitriding step are continuously performed without opening the processing space to the atmosphere.

A method for producing a semiconductor substrate, characterized in that:

2. In addition to the chromium layer forming step and the nitriding step, the first crystal layer growing step is continuously performed without opening the processing space to the atmosphere.

The method of manufacturing a semiconductor substrate according to claim 1, wherein:

3. The chromium layer forming step, the nitriding step, and the first crystal layer growing step are continuously performed a plurality of times without opening the processing space to the atmosphere, and the chromium nitride film and the first crystal are formed. A plurality of multiple layers including a plurality of layers are stacked on the base substrate.

The method for producing a semiconductor substrate according to claim 2, wherein:

4. The chromium layer forming step and the first crystal layer growing step are performed by any one of a MO CVD method, a MO HVPE method, and a MOM BE method. Manufacture of the semiconductor substrate described in item 1. Manufacturing method.

5. The processing space is

The first space,

The second space,

A third space connecting the first space and the second space;

including

5. The method for manufacturing a semiconductor substrate according to any one of claims 1 to 4, wherein:

6. The method further comprises a second crystal layer growth step of growing a second crystal layer of the I I I nitride semiconductor on the first crystal layer at a temperature higher than the growth temperature of the first crystal layer,

In addition to the deposition layer forming step and the nitriding step, the first crystal layer growth step and the second crystal layer growth step may be performed by vapor deposition without opening the processing space to the atmosphere. Performed continuously

7. The method according to claim 6, further comprising a separation step of etching the chromium nitride film to separate a portion including the second crystal layer and the first crystal layer from the base substrate. Semiconductor substrate manufacturing method.

8. Further comprising a second crystal layer growth step of growing a second crystal layer of the I II nitride semiconductor on the multiple layer at a temperature higher than the growth temperature of the first crystal layer,

In addition to the deposition layer forming step and the nitriding step, the first crystal layer growth step and the second crystal layer growth step are performed by a vapor phase growth method to increase the processing space. It is done continuously without opening up.

The method for manufacturing a semiconductor substrate according to claim 3, wherein:

9. The method further comprises a separation step of etching the chromium nitride film of the multilayer to separate a portion including the second crystal layer and the first crystal layer adjacent thereto from the base substrate.

The method of manufacturing a semiconductor substrate according to claim 8.

1 0. Carrying-in process for carrying the base substrate into the processing space partitioned from the external space;

A chromium nitride film forming step of forming a chromium nitride film on the base substrate by vapor deposition;

A first crystal layer growth step for growing a first crystal layer of a group I I I nitride semiconductor on the chromium nitride film;

With

The chromium nitride film forming step and the first crystal layer growing step are continuously performed without opening the processing space to the atmosphere.

A method of manufacturing a semiconductor substrate.

1 1. The chromium nitride film forming step and the first crystal layer growing step are continuously performed a plurality of times without opening the processing space to the atmosphere, and the chromium nitride film and the first crystal layer are formed. The method for manufacturing a semiconductor substrate according to claim 10, wherein a plurality of multi-layers including: are stacked on the base substrate.

12. The chromium nitride film formation step and the first crystal layer growth step are performed by any one of a MO CVD method, a MO HVPE method, and a MOM BE method. A method for producing a semiconductor substrate according to 1.

1 3. The processing space is

The first space,

The second space,

A third space connecting the first space and the second space;

including

The method for manufacturing a semiconductor substrate according to claim 10 or 11, wherein:

14. Further comprising a second crystal layer growth step for growing a second crystal layer of an I II group nitride semiconductor on the first crystal layer at a temperature higher than a growth temperature of the first crystal layer,

In addition to the chromium nitride film formation step and the first crystal layer growth step, the second crystal layer growth step is continuously performed by vapor phase growth without opening the processing space to the atmosphere.

The method for manufacturing a semiconductor substrate according to claim 11, wherein:

15. The method further comprises a separation step of etching the chromium nitride film to separate a portion including the second crystal layer and the first crystal layer from the base substrate. The manufacturing method of the semiconductor substrate as described in any one of.

16. Further comprising a second crystal layer growth step of growing a second crystal layer of an I II nitride semiconductor on the multiple layer at a temperature higher than the growth temperature of the first crystal layer,

In addition to the deposition nitride film formation step and the first crystal layer growth step, the second crystal layer growth step is continuously performed by vapor phase growth without opening the processing space to the atmosphere. Be called

The method for manufacturing a semiconductor substrate according to claim 12, wherein:

17. The method further includes a separation step of etching the chromium nitride film of the multi-layer to separate a portion including the second crystal layer and the first crystal layer adjacent thereto from the base substrate.

17. The method for manufacturing a semiconductor substrate according to claim 16, wherein:

1 8. Carrying-in process of carrying the base substrate into the processing space partitioned from the external space;

Nitriding the nitride layer to form a chromium nitride film having a plurality of triangular pyramid-shaped microcrystalline portions; and

A first crystal layer growth step of growing a first crystal layer of a group I II I compound semiconductor on the chromium nitride film;

With

A method of manufacturing a semiconductor substrate.

19. The first crystal layer growth step is performed continuously without opening the processing space to the atmosphere in combination with the chromium layer deposition step and the nitridation step.

The method for manufacturing a semiconductor substrate according to claim 18, wherein:

2 0. Carrying-in process for carrying the base substrate into the processing space partitioned from the external space;

A vapor nitride film forming step of forming a vapor nitride film having a plurality of triangular pyramid-shaped microcrystal parts on the base substrate by vapor phase growth; A first crystal layer growth step of growing a first crystal layer of a Γ group II nitride semiconductor on the chromium nitride film;

With

A method of manufacturing a semiconductor substrate.

2 1. By the method for manufacturing a semiconductor substrate according to any one of claims 1 to 20, a preparation step of preparing the second crystal layer as a semiconductor substrate;

An element structure forming step of forming an element structure on the semiconductor substrate; and a method of manufacturing the element structure.