Semiconductor laser device and fabrication method thereof

• US 20030031219A1
• Filed: 03/26/2002
• Published: 02/13/2003
• Est. Priority Date: 08/08/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Nobuhiko Sawaki
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Nobuhiko Sawaki
• Inventors: Ito, Shigetoshi, Ono, Tomoki, Honda, Yoshio, Koide, Norikatsu, Kameshiro, Norifumi, Sawaki, Nobuhiko, Furukawa, Katsuki, Yamaguchi, Masahito
• Granted Patent: US 6,888,867 B2
• Time in Patent Office: Days
• US Class Current: 372/45
• CPC Class Codes: H01S 2304/00 Special growth methods for semiconductor lasers
• CPC Class Codes: H01S 5/0207 Substrates having a special shape
• CPC Class Codes: H01S 5/021 Silicon based substrates
• CPC Class Codes: H01S 5/3203 on non-planar substrates to create thickness or compositional variations
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

A semiconductor laser device includes a substrate and an n-GaN layer composed of a nitride semiconductor formed on the substrate. The substrate includes a trench having as a slope a plane inclined 62 degrees from the main plane of the substrate, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane. The n-GaN layer is formed on the slope. On the n-GaN layer are formed a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor. The active layer has a plane orientation substantially matching the plane orientation of the main plane.

Claims

1. A semiconductor laser device comprising a substrate and a compound semiconductor layer composed of a nitride semiconductor formed on said substrate, said substrate including a trench having as a slope a plane inclined 62 degrees from a main plane of said substrate, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane, said compound semiconductor layer being formed on said slope, and including a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor, on said compound semiconductor layer, said active layer having a plane orientation substantially matching the plane orientation of said main plane.

5. The semiconductor laser device according to claim 1, wherein said substrate is formed of silicon.

6. The semiconductor laser device according to claim 1, wherein said upper clad layer and said lower clad layer are formed of a nitride semiconductor containing Al.

8. The semiconductor laser device according to claim 1, wherein said compound semiconductor layer has a <

0001>

direction substantially perpendicular to said slope.

9. The semiconductor laser device according to claim 1, wherein said active layer has a (1-101) plane as a plane orientation.

10. The semiconductor laser device according to claim 1, wherein said trench extends along a [11-20] direction of the nitride semiconductor constituting said active layer.

11. The semiconductor laser device according to claim 1, wherein a laser beam waveguide stripe structure is formed along said trench.

12. The semiconductor laser device according to claim 1, wherein a film having growth of a nitride semiconductor suppressed is formed at at least a portion of a surface of said substrate other than said slope.

2. A semiconductor laser device comprising a substrate and a compound semiconductor layer composed of a nitride semiconductor formed on said substrate, said substrate including a trench having as a slope a plane inclined 62 degrees from a main plane of said substrate, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane, said compound semiconductor layer being formed on said slope, and including a lower clad layer composed of a nitride semiconductor, an active layer composed of a nitride semiconductor, and an upper clad layer on said compound semiconductor layer, said lower clad layer and upper clad layer being composed of a nitride semiconductor containing Al.

7. The semiconductor laser device according to claim 2, wherein said active layer has a plane orientation substantially matching the plane orientation of the main plane of said substrate.

3. A semiconductor laser device comprising a silicon substrate, and a compound semiconductor layer composed of a nitride semiconductor formed on said silicon substrate, said silicon substrate including a trench having as a slope a plane inclined 62 degrees from a main plane of said silicon substrate, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane, said compound semiconductor layer being formed on said slope, and including a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor.

4. A semiconductor laser device comprising a silicon substrate, and a compound semiconductor layer composed of a nitride semiconductor formed on said silicon substrate, said compound semiconductor layer being formed using a silicon substrate having a main plane composed of a plane corresponding to a (100) plane rotated 7.3 degrees about a [01-1] axis or a plane inclined in a range within 3 degrees in an arbitrary direction from the rotated plane, said silicon substrate including a trench having a (111) plane as a slope, said compound semiconductor layer being formed on said slope, and including a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor.

13. A fabrication method of a semiconductor laser device comprising the steps of:

forming at a main plane of a substrate, a trench having as a slope a plane inclined 62 degrees from said main plane, or a plane inclined within 3 degrees in an arbitrary direction from the inclined plane,

growing crystal of a nitride semiconductor on said slope to form a compound semiconductor layer,

sequentially stacking on said compound semiconductor layer a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor.

15. The fabrication method of a semiconductor laser device according to claim 13, further comprising the step of forming a film having growth of a nitride semiconductor suppressed at at least a portion of a surface of said substrate other than said slope, prior to forming said compound semiconductor layer.

16. The fabrication method of a semiconductor laser device according to claim 13, wherein said trench is provided in plurality on said substrate, and said compound semiconductor layer formed on the slope of said trench is combined as crystal growth proceeds.

17. The fabrication method of a semiconductor laser device according to claim 16, further comprising the step of removing said substrate after said compound semiconductor layer is formed.

18. The fabrication method of a semiconductor laser device according to claim 13, wherein said crystal of a nitride semiconductor is grown so that a <

0001>

direction of said compound semiconductor layer is substantially perpendicular to said slope.

19. The fabrication method of a semiconductor laser device according to claim 13, wherein said upper clad layer and said lower clad layer are formed of a nitride semiconductor containing Al.

20. The fabrication method of a semiconductor laser device according to claim 13, wherein crystal is grown so that said active layer has a plane orientation substantially matching the plane orientation of the main plane of said substrate.

21. The fabrication method of a semiconductor laser device according to claim 20, wherein said active layer has a (1-101) plane as a plane orientation.

14. A fabrication method of a semiconductor laser device comprising the steps of:

forming a trench having a (111) plane as a slope at a main plane of a silicon substrate having said main plane composed of a plane corresponding to a (100) plane rotated 7.3 degrees about a [01-1] axis, or a plane inclined in a range within 3 degrees in an arbitrary direction from the rotated plane,

growing crystal of a nitride semiconductor on said slope to form a compound semiconductor layer, and

sequentially stacking on said compound semiconductor layer a lower clad layer, an active layer, and an upper clad layer, each composed of a nitride semiconductor.