Nitride semiconductor laser element and optical device containing it

• US 20040113141A1
• Filed: 07/14/2003
• Published: 06/17/2004
• Est. Priority Date: 01/15/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Isuda, Yuhzoh, Ito, Shigetoshi, Taneya, Mototaka, Yamasaki, Yukio, Yuasa, Takayuki
• Granted Patent: US 6,891,201 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/0075 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 5/2231 with inner confining structure only between the active layer and the upper electrode
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A nitride semiconductor light emitting device includes a processed substrate (101a) including a groove and a hill formed on a main surface of a nitride semiconductor substrate, a nitride semiconductor underlayer (102) covering the groove and the hill of the processed substrate, and a light emitting device structure having a light emitting layer (106) including a quantum well layer or a quantum well layer and a barrier layer in contact with the quantum well layer between an n type layer (103-105) and a p type layer (107-110) over the nitride semiconductor underlayer. A current-constricting portion of the light emitting device structure is formed above a region more than 1 μm away from the center of the groove in the width direction and more than 1 μm away from the center of the hill in the width direction.

Claims

1. A nitride semiconductor laser device, comprising:

a processed substrate (101a) including a groove and a hill formed on a main surface of a nitride semiconductor substrate;

a nitride semiconductor underlayer (102) covering the groove and the hill of said processed substrate; and

a light emitting device structure having a light emitting layer (106) including a quantum well layer or a quantum well layer and a barrier layer in contact with the quantum well layer between an n type layer (103-105) and a p type layer (107-110) over said nitride semiconductor underlayer,

a current-constricting portion (RS) of said light emitting device structure being formed above a region more than 1 μ

m away from the center of said groove in the width direction and more than 1 μ

m away from the center of said hill in the width direction.

2. The nitride semiconductor laser device according to claim 1, wherein said current-constricting portion is formed above a region more than 1 μ

m away from the center of said groove in the width direction and within the width of said groove.

3. The nitride semiconductor laser device according to claim 1, wherein said current-constricting portion is formed above a region more than 1 μ

m away from the center of said groove in the width direction and across the groove and the hill.

4. The nitride semiconductor laser device according to claim 1, wherein at least either of the width of said groove and the width of said hill is in a range of 4-30 μ

m.

5. The nitride semiconductor laser device according to claim 1, wherein the width of said groove is wider than the width of said hill.

6. The nitride semiconductor laser device according to claim 1, wherein said groove has a depth in a range of 1-10 μ

m.

7. The nitride semiconductor laser device according to claim 1, wherein said nitride semiconductor underlayer is formed of GaN containing at least one impurity selected from Si, O, Cl, S, C, Ge, Zn, Cd, Mg and Be in a range from 1×

10¹⁷/cm³ to 5×

10¹⁸/cm³.

8. The nitride semiconductor laser device according to claim 1, wherein said nitride semiconductor underlayer includes Al_xGa_1-xN (0.01≦

x≦

0.15).

9. The nitride semiconductor laser device according to claim 1, wherein said nitride semiconductor underlayer includes In_xGa_1-xN (0.01≦

x≦

0.18).

10. The nitride semiconductor laser device according to claim 1, wherein said quantum well layer contains at least one of As, P and Sb.

11. An optical apparatus including the nitride semiconductor laser device of claim 1.

12. A nitride semiconductor laser device, comprising:

a mask substrate (101 m) including a mask pattern formed on a main surface of a nitride semiconductor substrate,

said mask pattern including a plurality of stripe masks (200) and a plurality of stripe windows arranged alternately, each said mask being formed of a growth inhibiting film for suppressing epitaxial growth of a nitride semiconductor layer thereon, and each said window being unprovided with said growth inhibiting film;

a nitride semiconductor underlayer (102) covering said mask pattern; and

a light emitting device structure having a light emitting layer (106) including a quantum well layer or a quantum well layer and a barrier layer in contact with the quantum well layer between an n type layer (103-105) and a p type layer (107-110) over the underlayer,

a current-constricting portion (RS) through which substantial electric current is introduced into said light emitting device structure being formed above a region more than 1 μ

m away from the center of said mask in the width direction and more than 1 μ

m away from the center of said window in the width direction.

13. The nitride semiconductor laser device according to claim 12, wherein said current-constricting portion is formed above a region more than 1 μ

m away from the center of said mask in the width direction and within a width of said mask.

14. The nitride semiconductor laser device according to claim 12, wherein said current-constricting portion is formed above a region across said mask and said window.

15. The nitride semiconductor laser device according to claim 12, wherein said mask has a width of more than 5 μ

m and less than 30 μ

m.

16. The nitride semiconductor laser device according to claim 12, wherein said window has a width of more than 2 μ

m and less than 20 μ

m.

17. The nitride semiconductor laser device according to claim 12, wherein the width of said mask is wider than the width of said window.

18. The nitride semiconductor laser device according to claim 12, wherein said nitride semiconductor underlayer includes Al_xGa_1-xN (0.01≦

x≦

0.15).

19. The nitride semiconductor laser device according to claim 12, wherein said nitride semiconductor underlayer includes In_xGa_1-xN (0.01≦

x≦

0.18).

20. The nitride semiconductor laser device according to claim 12, wherein said quantum well layer contains at least one of As, P and Sb.

21. The nitride semiconductor laser device according to claim 12, wherein said nitride semiconductor substrate contains at least one impurity selected from Si, O, Cl, S, C, Ge, Zn, Cd, Mg and Be in a concentration range of more than 5×

10¹⁷/cm³ and less than 5×

10¹⁸/cm³.

22. A semiconductor optical apparatus including the nitride semiconductor laser device of claim 12.