Method of crystallizing a nitride III-V compound semiconductor layer on a sapphire substrate

• US 7,033,854 B2
• Filed: 02/28/2001
• Issued: 04/25/2006
• Est. Priority Date: 06/26/1998
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Morita, Etsuo
• Primary Examiner(s): Pham, Hoai
• Assistant Examiner(s): Ha, Nathan W.
• Application Number:
  US09/795,844
• Publication Number:
  US 20010010941A1
• Time in Patent Office: 1,882 Days
• Field of Search: 438/40, 438/47, 438/48, 438/49, 438/50, 438/53, 438/54
• US Class Current: 438/40
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/0243 Surface structure
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 29/66462 with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01S 5/0207 Substrates having a special shape
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

To improve crystallographic property of a nitride III-V compound semiconductor layer grown on a sapphire substrate, a plurality of recesses are made on a major surface of the sapphire substrate, and the nitride III-V compound semiconductor layer is grown thereon. At least a part of the inner surface of each recess makes an angle not less than 10 degrees with respect to the major surface of the sapphire substrate. The recesses are buried with nitride III-V compound semiconductor crystal having a higher Al composition ratio than the nitride III-V compound semiconductor layer, such as Al_xGa_1-xN crystal whose Al composition ratio x is 0.2 or more, for example. Each recess has a depth not less than 25 nm and a width not less than 30 nm. The recesses may be made either upon thermal cleaning of the sapphire substrate or by using lithography and etching, thermal etching, or the like.

Claims

1. A manufacturing method of a semiconductor device using a nitride III-V compound semicoductor layer grown on a sapphire substrate, comprising:

first forming recesses on a major surface of said sapphire substrate using thermal cleaning, and thereafter growing said nitride III-V compound semiconductor layer on said major surface of said sapphire substrate,

wherein said nitride III-V compound semiconductor layer is grown after first growing a buffer layer made of a nitride III-V compound semiconductor on said major surface of the sapphire substrate at a first substrate temperature, while raising the substrate temperature from said first temperature to a second temperature higher than said first temperature.

2. The manufacturing method of a semiconductor device according to claim 1, wherein nitride III-V compound semiconductor crystal having a higher Al composition ratio than said nitride III-V compound semiconductor layer is made to at least plug said recesses of the sapphire substrate by one of crystallizing said buffer layer plugged inside said recesses of said sapphire substrate and making Al diffuse from said sapphire substrate into said buffer layer by annealing while the substrate temperature is raised.

3. The manufacturing method of a semiconductor device according to claim 2, wherein each said recess has a depth not less than 10 nm and a width not less than 30 nm.

4. The manufacturing method of a semiconductor device according to claim 1, wherein said major surface of said sapphire substrate is nitrided prior to growth of said buffer layer.

5. A manufacturing method of a semiconductor device using a nitride III-V compound semiconductor layer grown on a sapphire substrate, comprising:

first forming recesses on a major surface of said sapphire substrate, and thereafter growing said nitride III-V compound semiconductor layer on said major surface of said sapphire substrate;

wherein a buffer layer made of a nitride III-V compound semiconductor is grown on said sapphire substrate while raising the substrate temperature from a first temperature to a second temperature higher than said first temperature.

6. The manufacturing method of a semiconductor device to claim 5, wherein nitride III-V compound semiconductor crystal having a higher Al composition ratio than said nitride III-V compound semiconductor layer is made to at least plug said recesses of the sapphire substrate by one of crystallizing said buffer layer plugged inside said recesses of said sapphire substrate and making Al diffuse from said sapphire substrate into said buffer layer by annealing while the substrate temperature is raised.

7. The manufacturing method of a semiconductor device according to claim 6, wherein each said recess has a depth not less than 10 nm and a width not less than 30 nm.

8. The manufacturing method of a semiconductor device according to claim 5 wherein said major surface of said sapphire substrate is nitrided prior to growth of said buffer layer.

9. A manufacturing method of a semiconductor device using a nitride III-V compound semiconductor layer grown on a sapphire substrate, comprising:

first forming recesses on a major surface of said sapphire substrate, and thereafter growing said nitride III-V compound semiconductor layer on said major surface of said sapphire substrate;

wherein said nitride III-V compound semiconductor layer is grown directly on said sapphire substrate while raising the substrate temperature from a first temperature to a second temperature higher than said first temperature.

10. The manufacturing method of semiconductor device according to claim 9, wherein nitride III-V compound semiconductor crystal having a higher Al At composition ratio than said nitride III-V compound semiconductor layer is made to at least plug said recesses of the sapphire substrate by one of crystallizing said nitride III-V compound semiconductor layer plugged inside said recesses of said sapphire substrate and making Al diffuse from said sapphire substrate into said nitride III-V compound semiconductor layer by annealing while the substrate temperature is raised.

11. The manufacturing method of a semiconductor device according to claim 10, wherein each said recess has a depth not less than 10 nm and a width not less than 30 nm.

12. The manufacturing method of a semiconductor device according to claim 9, wherein said major surface of said sapphire substrate is nitrided prior to growth of aid nitride III-V compound semiconductor layer.