Nitride semiconductor laser and method of fabricating the same

• US 20040137655A1
• Filed: 01/07/2004
• Published: 07/15/2004
• Est. Priority Date: 05/10/1999
• Status: Abandoned Application

• Current Assignee: Pioneer Corporation
• Original Assignee: Pioneer Corporation
• Inventors: Tanaka, Toshiyuki, Ota, Hiroyuki, Chikuma, Kiyofumi
• Application Number:
  US10/751,959
• Publication Number:
  US 20040137655A1
• Time in Patent Office: Days
• US Class Current: 438/22
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01S 2304/04 MOCVD or MOVPE
• CPC Class Codes: H01S 5/0202 Cleaving
• CPC Class Codes: H01S 5/0215 Bonding to the substrate
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• 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

Abstract

A method for fabricating a nitride semiconductor laser device having crystal layers each made of a group III nitride semiconductor (Al_xGa_1−x)_1−yIn_yN (0≦x≦1, 0≦y≦1) layered in order on a ground layer (Al_x′Ga_1−x′)_1−y′In_y′N (0≦x′≦1, 0≦y′≦1). The method including a step of forming a plurality of crystal layers each made of group III nitride semiconductor on a ground layer formed on a substrate such as sapphire; a step of applying a light beam from the substrate side toward the interface between the substrate and the ground layer thereby forming the decomposed-matter area of a nitride semiconductor; a step of separating the ground layer carrying the crystal layers from the substrate along the decomposed-matter area; and a step of cleaving the ground layer thereby forming a cleavage plane of the crystal layers.

Claims

1. A method for fabricating a nitride semiconductor laser device having crystal layers each made of a group III nitride semiconductor (Al_xGa₁₋

x)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) layered in order on a ground layer (Al_x′

Ga<sub>1−

x′</sub>

)<sub>1−

y′</sub>

In_y′

N (0≦

x′

≦

1, 0≦

y′

≦

1), the method comprising the steps of;

forming a plurality of crystal layers each made of group III nitride semiconductor on a ground layer formed on a substrate, the crystal layers including an active layer;

applying a light beam from the substrate side toward the interface between the substrate and the ground layer thereby forming the decomposed-matter area of a nitride semiconductor;

separating the ground layer with the crystal layers thereon from the substrate along the decomposed-matter area; and

cleaving the ground layer thereby forming a cleavage plane of the crystal layers.

2. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein the substrate is made of sapphire.

3. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein the wavelength of the light beam is selected from wavelengths passing through the substrate and absorbed by the ground layer in the vicinity of the interface.

4. A method for fabricating a nitride semiconductor laser device according to claim 1 further comprising, between said step of forming the crystal layers and said step of applying the light beam toward the interface, a step of bonding a cleavable second substrate onto a surface of the crystal layers in such a manner that a cleavage plane of the second substrate substantially coincides with a cleavage plane of the crystal layers of the nitride semiconductor.

5. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein the cleavable second substrate is made of a semiconductor single-crystal material.

6. A method for fabricating a nitride semiconductor laser device according to claim 5, wherein the semiconductor single-crystal material is selected from a group consisting of GaAs, InP and Si.

7. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein, in the step of applying the light beam toward the interface, the light beam is applied uniformly or entirely onto the interface between the substrate and the ground layer.

8. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein, in the step of applying the light beam toward the interface, the interface between the substrate and the ground layer is scanned with a spot or line of the light beam.

9. A method for fabricating a nitride semiconductor laser device according to claim 1 further comprising a step of forming a waveguide extending along a direction normal to the cleavage plane of the nitride semiconductor.

10. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein the crystal layers of the nitrid semiconductor are formed by metal-organic chemical vapor d position.

11. A method for fabricating a nitride semiconductor laser device according to claim 1, wherein, in the step of applying the light beam toward the interface, the light beam Is an ultraviolet ray generated from a frequency quadrupled YAG laser.

12. A nitride semiconductor laser device having successively grown crystal layers each made of a group III nitride semiconductor (Al_xGa₁₋

x)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) comprising;

a ground layer made of group III nitride semiconductor (Al_x′

Ga<sub>1−

x′</sub>

)<sub>1−

y′</sub>

In_y′

N (0≦

x′

≦

1, 0≦

y′

≦

1);

a plurality of crystal layers each made of group III nitride semiconductor formed on the ground layer;

a cleavable substrate bonded onto a surface of the crystal layers opposite to the ground layer.

13. A nitride semiconductor laser device according to claim 12, wherein the device further comprises a heat sink bonded onto the ground layer.

14. A nitride semiconductor laser device according to claim 12, wherein the device further comprises a heat sink bonded onto the cleavable substrate.

15. A nitride semiconductor laser device according to claim 12, wherein the cleavable substrate has a cleavage plane coinciding with a cleavage plane of the crystal layers of the nitride semiconductor.

16. A nitride semiconductor laser device according to claim 12, wherein the device further comprises a waveguide extending along a direction normal to the cleavage plane of th nitride semiconductor.

17. A nitride semiconductor laser device according to claim 12, wherein the cleavable substrate is made of a semiconductor single-crystal material.

18. A nitride semiconductor laser device according to claim 17, wherein the semiconductor single-crystal material is selected from a group consisting of GaAs, InP and Si.

19. A nitride semiconductor laser device according to claim 12, wherein the cleavable substrate is made of an electrically conductive material.