JP3440873B2 - Method for manufacturing group III nitride compound semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a group III nitride compound semiconductor device.

[0002]

2. Description of the Related Art A group III nitride compound semiconductor device such as a blue light emitting device is formed of Al _x Ga on a sapphire substrate.
_A buffer layer made of _1-xN (0 ≦ X ≦ 1) is grown by a metal organic chemical vapor deposition method (“MOCVD method” in this specification), and a group III nitride compound semiconductor layer is also formed thereon. It was obtained by growing by MOCVD method. In the MOCVD method, ammonia gas and a Group III alkyl compound gas such as trimethylaluminum (TMA), trimethylgallium (TMG), and trimethylindium (TMI) are supplied onto a substrate heated at an appropriate temperature to thermally decompose the substrate. Then, a desired crystal is formed on the substrate. Here, an organic metal such as TMA, which is a raw material gas for the buffer layer, is expensive, which has been one of the factors that push up the cost of the group III nitride compound semiconductor device.

If a buffer layer made of Al _x Ga _1-x N (0≤X≤1) is formed by a method other than the MOCVD method,
The use of organic metals is avoided. For example, Japanese Patent Publication 5-86
In Japanese Patent No. 646, an Al _x Ga _1-x N (0 ≦ X ≦ 1) buffer layer is formed by a high frequency sputtering method, and then N
Heating (800-1000 ° C.) in an atmosphere containing H ₃ gas (NH ₃ and N ₂ according to the example), and III
Supplying an organic metal of group III to decompose the organic metal of group III on the heated substrate to vapor-deposit the nitride film,
Al _x Ga _1-x N (0 ≦ X) having the same composition on the buffer layer.
It has been proposed to grow ≦ 1). The raw materials for forming the buffer layer made of Al _x Ga _1-x N (0 ≦ X ≦ 1) by the high frequency sputtering method are high-purity metallic aluminum and metallic gallium, and using these as targets, mixing argon and nitrogen. The gas is the sputter gas. In this case, all raw materials are cheap. Therefore, the cost of the device can be reduced as compared with the case where the buffer layer is formed by the MOCVD method using an expensive organic metal as a raw material.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
When the method disclosed in Japanese Patent Publication No.-86646 was tried, Al _x Ga _1-x N formed by the high frequency sputtering method was tried.
The crystallinity of the group III nitride compound semiconductor layer formed by the MOCVD method on the buffer layer of (0 ≦ X ≦ 1) did not satisfy the requirements of the present inventors. That is, Al _x Ga _1-x N (0 ≦
The crystallinity of the group III nitride compound semiconductor layer obtained by this method is inferior to that of the group III nitride compound semiconductor layer formed by the MOCVD method on the buffer layer of x ≦ 1). there were.

[0005]

Means for Solving the Problems The present inventors
As a result of intensive studies to improve the crystallinity of the group nitride compound semiconductor layer, a DC magnetron sputtering method
When a buffer layer made of a group II nitride compound semiconductor is formed, when the buffer layer is heat-treated in an atmosphere of a mixed gas of hydrogen gas and ammonia gas, a second group III nitride formed on the buffer layer is formed. The inventors have found that the crystallinity of the compound semiconductor layer is improved, and have conceived the present invention.

The structure of the present invention is as follows. A first group III-nitride compound semiconductor layer is formed on a substrate by a method not using an organic metal as a raw material (step 1), and the first group III-nitride compound semiconductor layer is mixed with hydrogen gas and ammonia gas. Heat treatment in an atmosphere of the mixed gas (step 2), and then forming a second group III-nitride compound semiconductor layer on the first group III-nitride compound semiconductor layer (step 3). A method for manufacturing a group III nitride compound semiconductor device, comprising:

The inventors of the present invention have an RHEED pattern of an AlN layer as an example of the first group III nitride compound semiconductor layer formed up to step 2 as described above,
The RHEED pattern of the AlN layer was also photographed when step 2 was omitted in the above manufacturing method.
Comparing the two, it was found that the former spot intensity was stronger than the latter spot intensity. Therefore, the first I
By performing the step 2 in which the group II nitride compound semiconductor layer is heat-treated in an atmosphere of a mixed gas of hydrogen gas and ammonia gas, improvement in crystallinity of the first group III nitride compound semiconductor layer can be confirmed. .

The manufacturing method of the present invention will be described in detail below. (Step 1) In Step 1, the first group III nitride compound semiconductor layer is formed on the substrate by a method other than the method using an organic metal as a raw material. Here, the first Group III nitride compound semiconductor _{Al x Ga Y In 1-x} -Y N
Quaternary compound semiconductor represented by (0 <X <1, 0 <Y <1, 0 <X + Y <1), Al _x Ga _1-x N (0 <
A ternary compound semiconductor represented by X <1), and A
1N, GaN and InN are included.

As a method in which an organic metal is not used as a raw material, there are a sputtering method including a reactive sputtering method (in particular, a DC magnetron sputtering method), a vapor deposition method, an ion plating method, a laser ablation method and an ECR method. According to this method, metallic aluminum, metallic gallium, metallic indium and nitrogen gas or ammonia gas are used as raw materials for forming the buffer layer made of the first Group III nitride compound semiconductor. In some cases, the first group III nitride compound semiconductor itself is targeted and used as it is. In any case, these raw materials are cheaper than organic aluminum. The thickness of the first group III-nitride compound semiconductor layer is not particularly limited, but MOC
100 to 3 like the conventional buffer layer formed by the VD method
It is preferably 000Å. More preferably 100
To 2000 Å, more preferably 100 to 30
It is 0Å. In addition to sapphire, the substrate material may be silicon, silicon carbide, zinc oxide, gallium phosphide, gallium arsenide, magnesium oxide, manganese oxide, or the like.

A buffer layer made of AlN was formed on a sapphire substrate using a DC magnetron sputtering apparatus under the following conditions, using high-purity metallic aluminum and nitrogen gas as raw materials, and reactive sputtering.

(Step 2) In Step 2, the first Group III nitride compound semiconductor layer formed by the sputtering method or the like as described above is heat-treated in an atmosphere of a mixed gas of hydrogen gas and ammonia gas. Thereby, the first I
The crystallinity of the group II nitride compound semiconductor layer is improved. I
As an example of the group II nitride compound semiconductor layer, the AlN layer of sample a (without heat treatment) and the sample A of Table d above
The 1N layer (without heat treatment) and the AlN layer of the sample a in an atmosphere of hydrogen gas: ammonia gas = 1: 0.3
Each RHEED pattern that was heat-treated at 00 ° C. (5 minutes) was photographed.

No spots were observed in the AlN layer of sample d obtained by growing the AlN layer at room temperature, and it was found that AlN was in an amorphous state. RHEED pattern when the AlN layer of sample a obtained by growing at 430 ° C. was further heat-treated in an atmosphere of a mixed gas of hydrogen gas and ammonia gas, and RHEED pattern of the AlN layer of sample a in which the heat treatment was omitted. From the comparison, it was confirmed that the heat treatment in a mixed gas atmosphere of hydrogen gas and ammonia gas improves the crystallinity of the AlN layer.

The mixing ratio of hydrogen gas and ammonia gas is
The flow rate ratio is preferably hydrogen gas: ammonia gas = 1: 0.1-1. More preferably, hydrogen gas: ammonia gas = 1: 0.1 to 0.5, and even more preferably hydrogen gas: ammonia gas = 1: 0.3. The heating condition is preferably 1000 to 1250 ° C. The temperature is more preferably 1050 to 1200 ° C, still more preferably 1100 to 1150 ° C.

(Step 3) In Step 3, the first II
A second group III nitride compound semiconductor layer is formed on the group I nitride compound semiconductor layer. The second group III nitride compound semiconductor has a general formula of Al _X Ga _Y In.
_1-X-Y N (0≤x≤1, 0≤Y≤1, 0≤X + Y≤
Although represented by 1), it may further contain boron (B) and thallium (Tl) as group III elements, and part of nitrogen (N) may be phosphorus (P) or arsenic (As). ,
It may be replaced with antimony (Sb) or bismuth (Bi). The group III nitride compound semiconductor may contain any dopant. The method for forming the group III nitride compound semiconductor layer is not particularly limited. For example, a well-known organometallic compound vapor phase epitaxy method (in this specification, “MO
CVD method ". ). It can also be formed by a known molecular beam crystal growth method (MBE method), a halide vapor phase growth method (HVPE method), or the like.

Growth of Group III nitride compound semiconductor
When the OCVD method is used, the sample is set on the susceptor of the MOCVD apparatus, and the step 2 is performed in the reaction apparatus.
Is preferable from the viewpoint of reducing the manufacturing process. In this case, the upper limit of the heat treatment temperature is defined by the performance of the reactor. In a general-purpose MOCVD apparatus, the upper limit of the reaction temperature is 1250 ° C. This is because quartz is used for the component parts, and when quartz is not used, heat treatment at a higher temperature becomes possible. Further, it is preferable that the growth temperature of the second Group III nitride compound semiconductor layer and the heat treatment temperature are substantially the same because temperature control becomes easy.

The AlN layers of Samples a to d in Table 1 were heated at 1000 ° C. in an atmosphere of hydrogen gas: ammonia gas = 1: 0.3.
Heat treatment was performed for 5 minutes, and a GaN layer having a thickness of 1 μm was formed on each of them at 1100 ° C. by MOCVD. An optical micrograph of the surface of each GaN layer thus obtained was taken. As a result, the surface of the GaN layer formed on the AlN layers of Samples a to c became a mirror surface. Therefore,
Further, another group III nitride compound semiconductor layer can be grown thereon with good crystallinity. On the other hand, the surface of the GaN layer formed on the AlN layer of sample d was not a mirror surface. As a result, the GaN growth temperature is 900 to 12
The same tendency is shown in a wide range of 00 ° C.

From the above results, it is preferable that the temperature when the first group III nitride compound semiconductor layer is formed by a method not using organoaluminum as a raw material is 200 to 600 ° C. The temperature is more preferably 300 to 500 ° C, further preferably 400 to 500 ° C.

The AlN layers of Samples a to c in Table 1 were heated at 1000 ° C. in an atmosphere of hydrogen gas: ammonia gas = 1: 0.3.
Heat treatment was performed for (5 minutes), and a GaN layer having a thickness of 4 μm was formed thereon at 1100 ° C. by the MOCVD method. The reason why the thickness is set to 4 μm is that the group III nitride compound semiconductor layer having this thickness is formed on the buffer layer in a general light emitting device. Rocking curves of the GaN layers having a thickness of 4 μm thus obtained are shown in FIGS. 1 to 3. The rocking curve was obtained by executing a ω-2θ scan using an X-ray diffractometer (X-pert) manufactured by Philips. The crystallinity of the GaN layer in FIGS.
The crystallinity is equal to or higher than the crystallinity of the GaN layer also formed by the MOCVD method on the buffer layer made of a group III nitride compound semiconductor such as AlN formed by the MOCVD method. That is, the results of FIGS. 1 to 3 show that the second group III-nitride compound semiconductor layer formed on the buffer layer by sputtering and the heat treatment in a predetermined atmosphere can be sufficiently put to practical use. It supports that.

A semiconductor element is composed of the second group III nitride compound semiconductor layer thus formed.
The light-emitting element has a well-known double hetero structure or superlattice structure. Further, a functional device represented by an FET structure can also be constructed.

[0020]

EXAMPLE FIG. 4 shows a light emitting device 1 manufactured by the manufacturing method of the present invention. The specifications of each layer of the light emitting device 1 of the example are as follows.

To manufacture the light emitting device 1, first, the sapphire substrate 2 is set in a DC magnetron sputtering apparatus. AlN on sapphire substrate with high purity aluminum as target and argon gas and nitrogen gas as sputter gas
The buffer layer 3 made of a material is formed. At this time, the substrate is 430 ℃
Keep on. After that, the substrate 2 on which the buffer layer 3 is formed is taken out from the sputtering apparatus and set on the susceptor in the reaction chamber of the MOCVD apparatus. The substrate 2 is heated to 1000 ° C. or higher and hydrogen gas and ammonia gas are allowed to stand for 5 minutes while flowing 10 liter / min and 3 liter / min, respectively. After that, the n-clad layer 4, the light-emitting layer 5 and the p-clad layer 6 are grown according to the ordinary method of MOCVD.

After forming the p-clad layer 6, a part of the p-clad layer 6, the light emitting layer 5 and the n-clad layer 4 is removed by etching by reactive ion etching or the like. After that, the n-electrode 7 is formed on the etched surface of the n-clad layer 4 by vapor deposition. The transparent electrode 8 is a thin film containing gold, and is laminated so as to cover substantially the entire upper surface of the p-clad layer 6. The p-electrode 9 is also made of a material containing gold, and is formed on the translucent electrode 8 by vapor deposition.

Since the second group III nitride compound semiconductor of good quality can be formed by the present invention, a light emitting diode having a light emission efficiency similar to or higher than the conventional one can be prepared. Was found to be extremely useful.

The element to which the present invention is applied is not limited to the above-mentioned light emitting diode, but may be a light receiving diode, a laser diode, a solar cell, or other optical element, a rectifier, a thyristor, a bipolar element such as a transistor, or an FET.
It can also be applied to electronic devices such as unipolar elements such as, and microwave elements. The present invention is also applied to a laminated body as an intermediate body of these elements.

The present invention is not limited to the above description of the embodiments and examples of the invention, and includes various modifications which can be conceived by those skilled in the art without departing from the scope of the claims.

The following matters will be disclosed below. (15) The method not using the organic metal as a raw material is DC
The manufacturing method according to claim 4, which is a magnetron sputtering method. (16) The first group III nitride compound semiconductor layer contains at least one kind of group II, group IV and group VI elements as a dopant.
3. The method according to any one of 3 and (15). (17) The first group III nitride compound semiconductor layer made of AlN contains any one of Si, Ge, S, Te, Mg, and Zn as a dopant. 15. The production method according to any one of 15). (14-2) The device according to claim 14, wherein the substrate is sapphire. (14-3) The element (14-4) according to (14-2), wherein the group III nitride compound semiconductor is formed on the a-plane of the sapphire. The method not used for the sputtering is a sputtering method including a reactive sputtering method, a vapor deposition method, an ion plating method, a laser ablation method or E
The CR method is a CR method.
2) or the element as described in (14-3). (14-5) the first Group III nitride compound semiconductor layer is made of _{Al x Ga 1-x N (} 0 ≦ X ≦ 1), according to claim 14, characterized in that, (14-2) - (14-
The device according to any one of 4). (14-6) The first group III-nitride compound semiconductor layer is made of AlN.
The element according to any one of (14-2) to (14-4). (14-7) The mixing ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: at a flow rate ratio.
It is 0.1-1, It is characterized by the above-mentioned.
The element according to any one of 4-2) to (14-6). (14-8) The mixing ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: at a flow rate ratio.
It is 0.1-0.5, It is characterized by the above-mentioned,
The element according to any one of (14-2) to (14-6). (14-9) The mixing ratio of the hydrogen gas and the ammonia gas is such that a flow rate ratio of hydrogen gas: ammonia gas is approximately 1: 0.3, and (14-9), (1)
The element according to any one of 4-2) to (14-6). (14-10) The heat treatment temperature of the first Group III nitride compound semiconductor layer is 1000 to 1250 ° C, and (14-2) to (14-).
The device according to any one of 9). (14-11) The second group III nitride compound semiconductor layer is formed by a method using an organic metal as a raw material.
14. The method according to claim 14, (14-2) to (14-).
The device according to any one of 10). (14-12) A method using the organic metal as a raw material is MOCVD (14-11).
The element described in 1. (14-13) The device according to (14-12), wherein the growth temperature of the group III nitride compound semiconductor by the MOCVD method is 1000 ° C. or higher. (14-15) The device according to (14-4), wherein the method in which the organic metal is not used as a raw material is a DC magnetron sputtering method. (14-16) The first group III nitride compound semiconductor layer is at least one of group II, group IV and group VI elements.
A seed is included as a dopant.
4, the element according to any one of (14-2) to (14-15). (14-17) The first group III nitride compound semiconductor layer made of AlN is made of Si, Ge, S, Te, Mg,
The element according to any one of claims 14 and (14-2) to (14-15), comprising any one of Zn as a dopant. (21) A first group III-nitride compound semiconductor layer is formed on a substrate by a method not using an organic metal as a raw material, and the first group III-nitride compound semiconductor layer is mixed with hydrogen gas and ammonia gas. Heat treatment in a mixed gas atmosphere, and then forming a second group III-nitride compound semiconductor layer on the first group III-nitride compound semiconductor layer. Method. (22) The manufacturing method according to (21), wherein the substrate is sapphire. (23) The group III nitride compound semiconductor is formed on the a-plane of the sapphire (2)
The manufacturing method according to 2). (24) As a method in which the organic metal is not used as a raw material, a sputtering method including a reactive sputtering method, a vapor deposition method, an ion plating method, a laser ablation method or ECR is used.
The method according to any one of (21) to (23), which is a method. (25) according to any one of the first Group III nitride compound semiconductor layer is made of _{Al x Ga 1-x N (} 0 ≦ X ≦ 1), it is characterized by (21) - (24) Manufacturing method. (26) The first group III nitride compound semiconductor layer is made of AlN (21) to (2)
The production method according to any one of 4). (27) The mixing ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: 0.1 in terms of flow rate ratio.
The manufacturing method according to any one of (21) to (26), characterized in that (28) The mixture ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: 0.1 in terms of flow rate ratio.
˜0.5, (21) ˜ (26)
The manufacturing method according to any one of 1. (29) The mixing ratio of the hydrogen gas and the ammonia gas is such that the flow ratio of hydrogen gas: ammonia gas is about 1:
It is 0.3, The manufacturing method in any one of (21)-(26) characterized by the above-mentioned. (30) The manufacturing method according to any one of (21) to (29), wherein the heat treatment temperature of the first Group III nitride compound semiconductor layer is 1000 to 1250 ° C. (31) The manufacturing method according to any of (21) to (30), wherein the second group III nitride compound semiconductor layer is formed by a method using an organic metal as a raw material. (32) The method using the organic metal as a raw material is MOC.
The manufacturing method according to (31), which is a VD method. (33) The manufacturing method according to (32), wherein the growth temperature of the group III nitride compound semiconductor by the MOCVD method is 1000 ° C. or higher. (34) A buffer layer made of a first group III nitride compound semiconductor and a second I formed on the buffer layer
A group III nitride compound semiconductor device having a group II nitride compound semiconductor layer, wherein the buffer layer is formed by a method not using an organic metal as a raw material, and the second group III nitride compound semiconductor is used. Before the formation of the above, the laminate is heat-treated in an atmosphere of a mixed gas of hydrogen gas and ammonia gas. (35) The method that does not use the organic metal as a raw material is DC
It is a magnetron sputtering method (2)
The manufacturing method according to 4). (36) The first group III nitride compound semiconductor layer contains at least one kind of group II, group IV and group VI elements as a dopant (21) to (3).
The method according to any one of 3) and (35). (37) The first group III-nitride compound semiconductor layer made of AlN contains any one of Si, Ge, S, Te, Mg, and Zn as a dopant (21) to (33). And the production method according to any one of (35). (34-2) The laminated body according to (34), wherein the substrate is sapphire. (34-3) The laminated body (34-4) according to (34-2), wherein the Group III nitride compound semiconductor is formed on the a-plane of the sapphire. Methods not used as raw materials include sputtering methods including reactive sputtering methods, vapor deposition methods, ion plating methods, laser ablation methods or E
CR method (34), (34-
2) or the laminated body as described in (34-3). (34-5) the first Group III nitride compound semiconductor layer is made of _{Al x Ga 1-x N (} 0 ≦ X ≦ 1), it is characterized by (34), (34-2) - (34-4)
The laminated body according to any one of 1. (34-6) The first group III nitride compound semiconductor layer is made of AlN (34),
The laminated body according to any one of (34-2) to (34-4). (34-7) The mixing ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: at a flow rate ratio.
(34), (34)
-2) to the laminated body according to any one of (34-6). (34-8) The mixing ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: at a flow rate ratio.
0.1-0.5, (34),
The laminate according to any one of (34-2) to (34-6). (34-9) The mixing ratio of the hydrogen gas and the ammonia gas is such that the flow ratio of hydrogen gas: ammonia gas is approximately 1: 0.3 (34), (34)
-2) to the laminated body according to any one of (34-6). (34-10) The heat treatment temperature of the first group III nitride compound semiconductor layer is 1000 to 1250 ° C. (34), (34-2) to (34-9).
The laminated body according to any one of 1. (34-11) The second group III nitride compound semiconductor layer is formed by a method using an organic metal as a raw material.
(34), (34-2) to (34-1)
The laminated body according to any one of 0). (34-12) A method of using the organic metal as a raw material is MOCVD (34-11).
The laminated body according to. (34-13) The laminated body according to (34-12), wherein the growth temperature of the group III nitride compound semiconductor by the MOCVD method is 1000 ° C. or higher. (34-15) The laminated body according to (34-4), wherein the method in which the organic metal is not used as a raw material is a DC magnetron sputtering method. (34-16) The first group III nitride compound semiconductor layer is at least one of group II, group IV and group VI elements.
Including a seed as a dopant (3
4) The laminated body according to any one of (34-2) to (34-15). (34-17) The first group III nitride compound semiconductor layer made of AIN is made of Si, Ge, S, Te, Mg,
Any of Zn is contained as a dopant, The laminated body in any one of (34), (34-2)-(34-15) characterized by the above-mentioned.

[Brief description of drawings]

FIG. 1 shows MOCV on an AlN buffer layer (Sample a in Table 1) formed by a DC magnetron sputtering method.
It is a figure which shows the rocking curve of the GaN layer formed by D method.

FIG. 2 shows MOCV on an AlN buffer layer (Sample b in Table 1) formed by a DC magnetron sputtering method.
It is a figure which shows the rocking curve of the GaN layer formed by D method.

FIG. 3 shows MOCV on an AlN buffer layer (sample c in Table 1) formed by DC magnetron sputtering.
It is a figure which shows the rocking curve of the GaN layer formed by D method.

FIG. 4 is a sectional view of a semiconductor light emitting device 1 of an example.

[Explanation of symbols]

1 Light emitting element 2 substrates 3 buffer layers 4 n cladding layer 5 Light emitting layer 6p clad layer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Ito No. 1 Nagahata Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Toyota Gosei Co., Ltd. Toyota Synthetic Co., Ltd. (72) Inventor Taishi Watanabe No. 1, Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Toyota Synthetic Co., Ltd. (56) Reference JP 9-134878 (JP, A) JP 60- 173829 (JP, A) JP 60-39819 (JP, A) JP 7-273048 (JP, A) JP 62-119196 (JP, A) JP 8-264899 (JP, A) JP-A-4-297023 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/205 H01L 33/00

Claims (14)

(57) [Claims] 1. A first group III nitride compound semiconductor layer is formed on a substrate by a method that does not use an organic metal as a raw material, and the first group III nitride compound semiconductor layer is replaced with hydrogen gas and ammonia gas. And heat treatment in an atmosphere of a mixed gas of, and then forming a second Group III nitride compound semiconductor layer on the first Group III nitride compound semiconductor layer,
A method for manufacturing a group III nitride compound semiconductor device, comprising: 2. The manufacturing method according to claim 1, wherein the substrate is sapphire. 3. The manufacturing method according to claim 2, wherein the group III nitride compound semiconductor is formed on the a-plane of the sapphire. 4. A method not using the organic metal as a raw material is a sputtering method including a reactive sputtering method, a vapor deposition method, an ion plating method, a laser ablation method or E.
It is CR method, The manufacturing method in any one of Claims 1-3 characterized by the above-mentioned. 5. The first group III-nitride compound semiconductor layer is made of Al _x Ga _1-x N (0 ≦ X ≦ 1), according to any one of claims 1 to 4. Manufacturing method. 6. The first to third group III-nitride compound semiconductor layers are made of AlN.
The manufacturing method according to any one of 1. 7. The mixing ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: at a flow rate ratio.
It is 0.1-1, The manufacturing method in any one of Claims 1-6 characterized by the above-mentioned. 8. The mixture ratio of the hydrogen gas and the ammonia gas is hydrogen gas: ammonia gas = 1: 1 in terms of a flow rate ratio.
It is 0.1-0.5, It is characterized by the above-mentioned.
The manufacturing method according to any one of 1. 9. The mixing ratio between the hydrogen gas and the ammonia gas is such that the flow ratio of hydrogen gas: ammonia gas is approximately 1: 0.3, and the mixing ratio is approximately 1: 0.3. The manufacturing method described. 10. The manufacturing method according to claim 1, wherein the heat treatment temperature of the first group III nitride compound semiconductor layer is 1000 to 1250 ° C. 11. The second group III nitride compound semiconductor layer is formed by a method using an organic metal as a raw material.
The manufacturing method according to any one of claims 1 to 10, characterized in that. 12. The manufacturing method according to claim 11, wherein the method of using the organic metal as a raw material is a MOCVD method. 13. The manufacturing method according to claim 12, wherein a growth temperature of the group III nitride compound semiconductor by the MOCVD method is 1000 ° C. or higher. 14. A Group III nitride compound semiconductor device having a buffer layer made of a first Group III nitride compound semiconductor and a second Group III nitride compound semiconductor layer formed on the buffer layer. The buffer layer is formed by a method not using an organic metal as a raw material, and is heat-treated under an atmosphere of a mixed gas of hydrogen gas and ammonia gas before forming the second group III nitride compound semiconductor. A group III nitride compound semiconductor device characterized by the above.