Method for fabricating a group III nitride semiconductor device

• US 6,335,218 B1
• Filed: 05/05/2000
• Issued: 01/01/2002
• Est. Priority Date: 05/10/1999
• Status: Expired due to Term

• Current Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Original Assignee: Pioneer Corporation
• Inventors: Ota, Hiroyuki, Kimura, Yoshinori, Miyachi, Mamoru
• Primary Examiner(s): CHRISTIANSON, KEITH ALAN
• Application Number:
  US09/565,025
• Time in Patent Office: 606 Days
• Field of Search: 438/5, 438/45, 438/46, 438/47, 438/507, 438/509, 438/935, 117/89, 117/93, 117/104, 117/201, 117/202, 117/952, 257/96, 257/97, 257/103, 372/43, 372/50
• US Class Current: 438/46
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02505 consisting of more than two layers
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/325 characterised by the doping materials
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

A group III nitride semiconductor device producing method is constructed by: a step of forming a first crystal layer made of a group III nitride semiconductor (Al_xGa_1−x)_1−y.In_yN (0≦×≦1, 0≦_y≦1) doped with a group II impurity element; a step of a second crystal layer made of a group III nitride semiconductor Al_zGa_1−zN (0.7≦z≦1) onto the first crystal layer; and a step of removing at least a part of the second crystal layer by etching after the formation of the first and second crystal layers.

Claims

1. A method of producing a group III nitride semiconductor device, comprising the steps of:

forming a first crystal layer by a metalorganic chemical vapor deposition method made of a group III nitride semiconductor (Al_xGa<sub>1−

x</sub>)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) doped with a group II impurity element;

forming a second crystal layer by a metalorganic chemical vapor deposition method made of a second group III nitride semiconductor Al_zGa<sub>1−

z</sub>N (0.7≦

z≦

1) onto the first crystal layer; and

removing at least a part of the second crystal layer by etching after the formation of the first and second crystal layers;

wherein a nitrogen precursor in the metalorganic compound chemical vapor deposition method is ammonia, and the amount of ammonia supplied into the reactor vessel is set much lower during the growth of the second crystal layer and the subsequent cooling step or during the cooling step alone than that for the growth of the first crystal layer.

5. A method according to claim 1, wherein the step of forming the second crystal layer is started at substantially the same temperature as a forming temperature of the first crystal layer.

2. A method of producing a group III nitride semiconductor device, comprising the steps of:

forming a first crystal layer by a metalorganic chemical vapor deposition method made of a group III nitride semiconductor (Al_xGa<sub>1−

x</sub>)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) doped with a group II impurity element;

forming a second crystal layer formed by a metalorganic chemical vapor deposition method made of a second group III nitride semiconductor Al_zGa<sub>1−

z</sub>N (0.7≦

z≦

1) onto the first crystal layer; and

removing at least a part of the second crystal layer by etching after the formation of the first and second crystal layers;

wherein a nitrogen precursor in the metalorganic compound chemical vapor deposition method is ammonia, and at the end of formation of the second crystal layer, the supply of ammonia is stopped earlier than the time of stopping the supply of a group III precursor to the reactor.

3. A method according to claim 2, wherein at the end of formation of the second crystal layer, when an indication of an ammonia detector falls below a threshold value, the supply of the group III precursor is stopped, and a cooling is performed.

6. A method according to claim 2, wherein the step of forming the second crystal layer is started at substantially the same temperature as a forming temperature of the first crystal layer.

7. A method according to claim 3, wherein the step of forming the second crystal layer is started at substantially the same temperature as a forming temperature of the first crystal layer.

4. A method of producing a group III nitride semiconductor device, comprising the steps of:

forming a first crystal layer made of a group III nitride semiconductor (Al_xGa<sub>1−

x</sub>)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) doped with a group II impurity element;

forming a second crystal layer made of a second group III nitride semiconductor Al_zGa<sub>1−

z</sub>N (0.7≦

z≦

1) onto the first crystal layer; and

removing at least a part of the second crystal layer by etching after the formation of the first and second crystal layers;

wherein the step of forming the second crystal layer includes a usage of nitrogen gas for a carrier gas.

8. A method according to claim 4, wherein the step of forming the second crystal layer is started at substantially the same temperature as a forming temperature of the first crystal layer.