Nitride semiconductor laser device
View Patent ↗A nitride semiconductor laser chip 103 is fixed to a submount 102 serving as a mount member with solder 107. The submount 102 is made of a material having a thermal expansion coefficient higher than that of a nitride semiconductor substrate, and has a thickness equal to or greater than 1.2 times the thickness of the layered nitride semiconductor structure composed of an n-type GaN substrate 1 and a layered nitride semiconductor portion 2. Between the n-type GaN substrate 1 and the submount 102 is laid a metal film having a thickness of from 1 to 50 μm.
1. A nitride semiconductor laser device comprising:
a nitride semiconductor laser chip composed of a nitride semiconductor substrate, a layered nitride semiconductor portion having a plurality of nitride semiconductor layers laid on a surface of the nitride semiconductor substrate, and electrodes; and
a mount member to which the nitride semiconductor laser chip is fixed, the mount member being made of a material having a thermal expansion coefficient higher than a thermal expansion coefficient of the nitride semiconductor substrate, the mount member having a thickness equal to or greater than 1.2 times a thickness of a layered nitride semiconductor structure composed of the nitride semiconductor substrate and the layered nitride semiconductor portion.
2. A nitride semiconductor laser device as claimed in claim 1 , wherein the nitride semiconductor laser chip is fixed to the mount member with a solder made of AuSn, AgSn, AuSi, AuGe, PbSn, InSn or AgCuSn or of a compound containing AuSn, AgSn, AuSi, AuGe, PbSn, InSn or AgCuSn.
3. A nitride semiconductor laser device as claimed in claim 2 , further comprising a stem having a submount comprising the mount member and having a chip mount portion formed thereon to which the submount is fixed.
4. A nitride semiconductor laser device as claimed in claim 3 , wherein the nitride semiconductor laser chip is fixed to the submount with a solder having a higher melting point than a solder with which the submount is fixed to the chip mount portion.
5. A nitride semiconductor laser device as claimed in claim 4 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
6. A nitride semiconductor laser device as claimed in claim 5 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
7. A nitride semiconductor laser device as claimed in claim 4 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
8. A nitride semiconductor laser device as claimed in claim 7 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
9. A nitride semiconductor laser device as claimed in claim 3 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
10. A nitride semiconductor laser device as claimed in claim 9 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
11. A nitride semiconductor laser device as claimed in claim 3 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
12. A nitride semiconductor laser device as claimed in claim 11 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
13. A nitride semiconductor laser device as claimed in claim 2 , further comprising a stem having a chip mount portion formed thereon, the chip mount porting comprising the mount member.
14. A nitride semiconductor laser device as claimed in claim 13 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
15. A nitride semiconductor laser device as claimed in claim 14 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
16. A nitride semiconductor laser device as claimed in claim 13 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
17. A nitride semiconductor laser device as claimed in claim 16 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
18. A nitride semiconductor laser device as claimed in claim 2 , further comprising a stem having a chip mount portion formed thereon, the mount member being fixed as a submount to the chip mount portion.
19. A nitride semiconductor laser device as claimed in claim 18 , wherein the nitride semiconductor laser chip is fixed to the submount with a solder having a higher melting point than a solder with which the submount is fixed to the chip mount portion.
20. A nitride semiconductor laser device as claimed in claim 19 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
21. A nitride semiconductor laser device as claimed in claim 20 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
22. A nitride semiconductor laser device as claimed in claim 19 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
23. A nitride semiconductor laser device as claimed in claim 22 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
24. A nitride semiconductor laser device as claimed in claim 18 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
25. A nitride semiconductor laser device as claimed in claim 24 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
26. A nitride semiconductor laser device as claimed in claim 18 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
27. A nitride semiconductor laser device as claimed in claim 26 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
28. A nitride semiconductor laser device as claimed in claim 2 , further comprising a stem having the mount member formed thereon as a chip mount portion.
29. A nitride semiconductor laser device as claimed in claim 28 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
30. A nitride semiconductor laser device as claimed in claim 29 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
31. A nitride semiconductor laser device as claimed in claim 28 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
32. A nitride semiconductor laser device as claimed in claim 31 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
33. A nitride semiconductor laser device as claimed in claim 1 , wherein the nitride semiconductor laser chip is, at a nitride semiconductor substrate side thereof, fixed to the mount member.
34. A nitride semiconductor laser device as claimed in claim 33 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 50 μm.
35. A nitride semiconductor laser device as claimed in claim 1 , wherein the nitride semiconductor laser chip is, at a layered nitride semiconductor portion side thereof, fixed to the mount member.
36. A nitride semiconductor laser device as claimed in claim 35 , wherein a metal layer laid between the layered nitride semiconductor structure and the mount member has a thickness of from 1 μm to 10 μm.
37. A nitride semiconductor laser device as claimed in claim 1 , wherein the electrodes of the nitride semiconductor laser chip are formed on a top surface of the layered nitride semiconductor portion and on a bottom surface of the nitride semiconductor substrate.
38. A nitride semiconductor laser device as claimed in claim 1 , wherein the mount member is made of Fe, Au, Cu, Ag, Al, Al—SiC, CuW 20 , BeO, CuW 15 , Al 2 O 3 , CuW 10 or GaAs.
39. A nitride semiconductor laser device as claimed in claim 1 , wherein the mount member is made of Fe, Au, Cu, Ag or Al.
40. A nitride semiconductor laser device comprising:
a nitride semiconductor laser chip composed of a nitride semiconductor substrate made of GaN, a layered nitride semiconductor portion having a plurality of nitride semiconductor layers laid on a surface of the nitride semiconductor substrate, and electrodes; and
a mount member to which the nitride semiconductor laser chip is fixed, the mount member being made of Cu or Fe having a thermal expansion coefficient higher than a thermal expansion coefficient of the nitride semiconductor substrate, the mount member having a thickness equal to or greater than 1.2 times a thickness of a layered nitride semiconductor structure composed of the nitride semiconductor substrate and the layered nitride semiconductor portion.
41. A nitride semiconductor laser device as claimed in claim 40 , wherein the nitride semiconductor laser chip is fixed to the mount member with a solder made of a compound containing AuSn or AgCuSn.