Nitrde semiconductor element and production method thereof

• US 20030139037A1
• Filed: 11/19/2002
• Published: 07/24/2003
• Est. Priority Date: 03/27/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kobayashi, Toshimasa, Nakajima, Hiroshi, Yamaguchi, Takashi, Yanashima, Katsunori
• Granted Patent: US 6,921,673 B2
• Time in Patent Office: Days
• US Class Current: 438/681
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/0265 Pendeoepitaxy
• CPC Class Codes: H01L 31/1852 comprising a growth substrate not being an AIIIBV compound
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01S 2304/12 Pendeo epitaxial lateral overgrowth [ELOG], e.g. for growing GaN based blue laser diodes
• CPC Class Codes: H01S 5/0207 Substrates having a special shape
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

Provided is a nitride semiconductor device with high reliability and high flexibility in design and manufacture of the device. The nitride semiconductor device comprises a seed crystal portion (11) formed on a sapphire substrate (10) and having a mask (12) on one side surface thereof, and a GaN layer (15) grown on the sapphire substrate (10) and the seed crystal portion (11) through epitaxial lateral overgrowth. The GaN layer (15) is grown only from an exposed side surface of the seed crystal portion (11) which is not covered with the mask (12), so the lateral growth of the GaN layer (15) is asymmetrically carried out. Thereby, a meeting portion (32) is formed in the vicinity of a boundary between the seed crystal portion (11) and the mask (12) in a thickness direction of the GaN layer (15). Therefore, as the meeting portion (32) is formed in a position away from the center between the adjacent seed crystal portions (11) in a direction parallel to a surface of the substrate, a width W_L of a lateral growth region is larger with respect to a pitch W_P of the seed crystal potion (11), compared with conventional configurations.

Claims

1. A nitride semiconductor device, comprising a plurality of seed crystal portions made of a nitride compound semiconductor and formed in stripes, and a crystal layer including a lateral growth region made of a nitride compound semiconductor and grown from the seed crystal portions as bases and a meeting portion on a substrate,

wherein the meeting portion is formed in a position away from a center between adjacent seed crystal portions in a direction parallel to a surface of the substrate.

2. A nitride semiconductor device according to claim 1, wherein

a mask is disposed on one side surface of the seed crystal portion or on one side surface and a top surface of the seed crystal portion.

3. A nitride semiconductor device according to claim 1, wherein

assuming that the sum of the width of the seed crystal portion and the width of a region between the adjacent seed crystal portions is W_P, and the width of the lateral growth region with a largest width is W_L, W_P and W_L satisfy a relationship of W_L∞

0.5W_P.

4. A nitride semiconductor device according to claim 3, further comprising a laser strip portion on the crystal layer,

wherein the laser stripe portion is disposed so as to correspond to the lateral growth region with the largest width.

5. A nitride semiconductor device according to claim 3, further comprising a source region, a gate region and a drain region on the crystal layer,

wherein the source region, the gate region and the drain region are disposed so as to correspond to the lateral growth region with the largest width.

6. A nitride semiconductor device, comprising a seed crystal layer made of a nitride compound semiconductor, a plurality of masks formed in stripes on the seed crystal layer, and a crystal layer including a lateral growth region made of a nitride compound semiconductor and grown on the seed crystal layer with the mask in between and a meeting portion on a substrate,

wherein the meeting portion is formed in a position away from a center line of the mask orthogonal to a surface of the substrate in a direction parallel to the surface of the substrate.

7. A nitride semiconductor device according to claim 6, wherein

the mask has a shape with an end and the other end of different thicknesses in a laminated direction.

8. A nitride semiconductor device according to claim 6, wherein

assuming that the sum of the width of the mask and the width of a region between adjacent masks is W_P, and the width of the lateral growth region with a largest width is W_L, W_P and W_L satisfy a relationship of W_L∞

0.5W_P.

9. A nitride semiconductor device according to claim 8, further comprising a laser stripe portion on the crystal layer,

wherein the laser stripe portion is disposed so as to correspond to the lateral growth region with the largest width.

10. A nitride semiconductor device according to claim 8, further comprising a source region, a gate region and a drain region on the crystal layer,

wherein the source region, the gate region and the drain region are disposed so as to correspond to the lateral growth region with the largest width.

11. A method of manufacturing a nitride semiconductor device, comprising the steps of:

forming a plurality of seed crystal portions made of a nitride compound semiconductor in stripes on a substrate;

forming a mask on one side surface of the seed crystal portion or on one side surface and a top surface of the seed crystal portion; and

forming a crystal layer made of a nitride compound semiconductor from the seed crystal portions as bases.

12. A method of manufacturing a nitride semiconductor device according to claim 11, wherein

assuming that the sum of the width of the seed crystal portion and the width of a region between adjacent seed crystal portions is W_P, a lateral growth region with a width of 0.5W_P or over is formed on the crystal layer.

13. A method of manufacturing a nitride semiconductor device according to claim 12, further comprising the step of:

forming a laser stripe portion so as to correspond to the lateral growth region after the crystal layer is formed.

14. A method of manufacturing a nitride semiconductor device according to claim 12, further comprising the step of:

forming a source region, a gate region and a drain region so as to correspond to the lateral growth region, after the crystal layer is formed.

15. A method of manufacturing a nitride semiconductor device according to claim 11, wherein

the crystal layer is formed through metal organic chemical vapor deposition (MOCVD).

16. A method of manufacturing a nitride semiconductor device, comprising the steps of:

forming a seed crystal layer made of a nitride compound semiconductor on a substrate;

forming a plurality of masks having a shape with an end and the other end of different thicknesses in a laminated direction in stripes on the seed crystal layer; and

forming a crystal layer made of a nitride compound semiconductor on the seed crystal layer with the masks in between.

17. A method of manufacturing a nitride semiconductor device according to claim 16, wherein

assuming that the sum of the width of the mask and the width of a region between adjacent masks is W_P, a lateral growth region with a width of 0.5W_P or over is formed on the crystal layer.

18. A method of manufacturing a nitride semiconductor device according to claim 17, further comprising the step of:

forming a laser stripe portion so as to correspond to the lateral growth region, after the crystal layer is formed.

19. A method of manufacturing a nitride semiconductor device according to claim 17, further comprising the step of:

forming a source region, a gate region and a drain region so as to correspond to the lateral growth region, after the crystal layer is formed.

20. A method of manufacturing a nitride semiconductor device according to claim 16, wherein

the crystal layer is formed through metal organic chemical vapor deposition (MOCVD).