Surface emitting semiconductor laser, its manufacturing method, and manufacturing method of electron device

• US 20050271106A1
• Filed: 06/02/2005
• Published: 12/08/2005
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tanaka, Yoshiyuki, Yamauchi, Yoshinori, Watanabe, Yoshiaki, Narui, Hironobu, Kuromizu, Yuichi
• Granted Patent: US 7,515,623 B2
• Time in Patent Office: Days
• US Class Current: 372/46.13
• CPC Class Codes: H01S 2301/166 Single transverse or lateral mode
• CPC Class Codes: H01S 5/0421 characterised by the semiconducting contacting layers electrodes H01S5/0425
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18388 Lenses
• CPC Class Codes: H01S 5/18394 Apertures, e.g. defined by the shape of the upper electrode

Abstract

A surface emitting semiconductor laser which can perform laser oscillation in a single peak beam like that in a single lateral mode and a manufacturing method which can easily manufacture such a laser at a high yield are provided. When a surface emitting semiconductor laser having a post type mesa structure is formed on an n-type semiconductor substrate, a mesa portion is formed and up to a p-side electrode and an n-side electrode are formed. Thereafter, a voltage is applied across the p-side and n-side electrodes and the laser is subjected to a steam atmosphere while extracting output light, thereby forming an Al oxide layer onto a p-type Al_wGa_1-wAs layer as a top layer of a p-type DBR layer and forming refractive index distribution like that of a concave lens.

Claims

1. A surface emitting semiconductor laser which comprises

a first reflective layer,

an active layer on said first reflective layer, and

a second reflective layer on said active layer and extracts output light from said second reflective layer,

wherein an oxide layer having predetermined refractive index distribution is formed on said second reflective layer.

2. A laser according to claim 1, wherein said predetermined refractive index distribution is obtained from distribution of a thickness and/or a composition of said oxide layer.

3. A laser according to claim 1, wherein said predetermined refractive index distribution is refractive index distribution like that of a concave lens.

4. A laser according to claim 1, wherein said oxide layer is an Al oxide layer.

5. A laser according to claim 1, wherein said oxide layer is formed by oxidizing a compound semiconductor layer containing Al.

6. A laser according to claim 5, wherein said compound semiconductor layer containing Al is a III-V group compound semiconductor layer containing Al.

7. A laser according to claim 6, wherein said III-V group compound semiconductor layer containing Al is an AlGaAs layer or an AlGaInP layer.

8. A laser according to claim 1, wherein each of said first reflective layer and said second reflective layer is made of a semiconductor multilayer film.

9. A laser according to claim 1, wherein each of said active layer and said second reflective layer has a cylindrical shape.

10. A laser according to claim 1, wherein a contact layer having a circular opening is formed on said second reflective layer and said oxide layer is formed on said second reflective layer in said opening of said contact layer.

11. A laser according to claim 10, wherein an electrode having a circular opening whose diameter is smaller than that of said opening of said contact layer is formed over said contact layer and said second reflective layer, and said oxide layer is formed on said second reflective layer in said opening of said electrode.

12. A laser according to claim 11, wherein an insulative layer is formed between said contact layer and said electrode.

13. A laser according to claim 1, wherein a protective film is provided so as to cover said oxide layer.

14. A manufacturing method of a surface emitting semiconductor laser which comprises

a first reflective layer,

an active layer on said first reflective layer, and

a second reflective layer on said active layer

and extracts output light from said second reflective layer,

wherein an oxide layer is formed on said second reflective layer by performing oxidization while irradiating light having predetermined intensity distribution.

15. A method according to claim 14, wherein said oxidization is performed while extracting the output light having said predetermined intensity distribution from said second reflective layer.

16. A method according to claim 14, wherein said oxidization is performed while irradiating the light having said predetermined intensity distribution from an outside.

17. A method according to claim 14, wherein said oxidization is performed while irradiating the light having said predetermined intensity distribution in a steam atmosphere.

18. A method according to claim 14, wherein said oxidization is performed while irradiating the light having said predetermined intensity distribution in a steam atmosphere whose temperature is equal to 60°

C. or more and whose humidity is equal to 60% or more.

19. A method according to claim 14, wherein said oxide layer has refractive index distribution-according to said predetermined intensity distribution.

20. A method according to claim 19, wherein said refractive index distribution is obtained from distribution of a thickness and/or a composition of said oxide layer.

21. A method according to claim 19, wherein said refractive index distribution is refractive index distribution like that of a concave lens.

22. A method according to claim 14, wherein said oxide layer is an Al oxide layer.

23. A method according to claim 14, wherein a compound semiconductor layer containing Al is formed in a top portion of said second reflective layer and, by oxidizing said compound semiconductor layer containing Al while irradiating the light having said predetermined intensity distribution, said oxide layer is formed.

24. A method according to claim 23, wherein said compound semiconductor layer containing Al is a III-V group compound semiconductor layer containing Al.

25. A method according to claim 24, wherein said III-V group compound semiconductor layer containing Al is an AlGaAs layer or an AlGaInP layer.

26. A method according to claim 14, wherein after said oxide layer is formed, a protective film is formed so as to cover said oxide layer.

27. A manufacturing method of an electron device having a compound semiconductor layer containing Al,

wherein an oxide layer is formed in said compound semiconductor layer containing Al by performing oxidization while irradiating light having predetermined intensity distribution.