Optical device, surface emitting type device and method for manufacturing the same

• US 20040169188A1
• Filed: 03/05/2004
• Published: 09/02/2004
• Est. Priority Date: 09/22/2000
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ishikawa, Masayuki, Nunoue, Shin-Ya
• Granted Patent: US 7,087,935 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/465 with a resonant cavity structure
• CPC Class Codes: H01S 2304/04 MOCVD or MOVPE
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/1835 Non-circular mesa
• CPC Class Codes: H01S 5/18361 Structure of the reflectors, e.g. hybrid mirrors
• CPC Class Codes: H01S 5/18363 comprising air layers
• CPC Class Codes: H01S 5/209 special etch stop layers
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

The present invention provides an optical device and a surface emitting type device which have high efficiency and a stable operation and are manufactured at high manufacturing yield. The optical device and the surface emitting type device are characterized in that they have a distributed Bragg reflector (DBR) including a plurality of semiconductor layers made of a nitride semiconductor with substantially same gaps therbetween. Further, the optical device and the surface emitting type device are characterized in that they have a distributed Bragg reflector (DBR) in which a plurality of semiconductor layers made of nitride semiconductor and a plurality of organic layers made of organic material are alternately laminated.

Claims

1. An optical device comprising a reflector for reflecting light, said reflector including a laminated layers having a plurality of semiconductor layers with substantially the same interval gaps therbetween, each of said semiconductor layers having substantially the same thickness and being made of a first nitride semiconductor containing aluminum.

2. An optical device according to claim 1, wherein said reflector is a reflector for reflecting light having a wavelength of λ

, and wherein each of said semiconductor layers has a refractive index of n₁ and a film thickness of λ

/4n₁.

3. An optical device according to claim 1, wherein the optical device further comprising a first support part interposed between the neighboring semiconductor layers, said support part containing a second nitride semiconductor having a lower content of aluminum than said first nitride semiconductor.

4. An optical device according to claim 3, wherein said first nitride semiconductor is Al_xGa_1-xN (0≦

x≦

1) and wherein said second nitride semiconductor is Al_yGa_1-yN (0≦

y<

x) or In_zGa_1-zN (0≦

z≦

1).

5. An optical device according to claim 1, wherein said reflector further has a second support part extending in the direction of lamination, wherein each of said semiconductor layers is connected to and supported by said second support part at the end portion of said second support part, and wherein said second support part includes a third nitride semiconductor having the same aluminum content as or a higher aluminum content than said first nitride semiconductor.

6. An optical device according to claim 1, wherein said optical device is a surface emitting type device and wherein said reflector is disposed so that it reflects light from an active layer of said surface emitting type device.

7. An optical device according to claim 6, wherein said active layer is made of a forth nitride semiconductor.

8. An optical device according to claim 1, wherein said optical device is a surface emitting type device in which a first reflecting portion for reflecting light from an active layer of said surface emitting type device and a second reflecting portion for reflecting light from said active layer are disposed so that they sandwich said active layer, and wherein at least one of said first reflecting portion and said second reflecting portion comprises said reflector.

9. An optical device according to claim 8, wherein said active layer is made of a fifth nitride semiconductor.

10. An optical device comprising a reflector for reflecting light, said reflector including a laminated layers in which a plurality of semiconductor layers, each of which has substantially the same thickness and is made of a first nitride semiconductor containing aluminum, and a plurality of organic layers, each of which has substantially the same thickness and is made of an organic material, are alternately laminated.

11. An optical device according to claim 10, wherein said reflector is a reflector for reflecting light having a wavelength of λ

, and wherein each of said semiconductor layers has a refractive index of n₃ and a film thickness of λ

/4n₃, and wherein each of said organic layers has a refractive index of n₄ and a film thickness of λ

/4n₄.

12. An optical device according to claim 10, wherein the organic material contains a transparent organic polymeric material which is one selected from the group consisting of poly-methyl methacrylate, polycarbonate, poly-diethylene glycol bisallyl carbonate, polystyrene, hard poly-vinyl chloride, styrene-methyl methacrylate copolymer, acrylonitrile-styrene copolymer, poly-cyclohexyl methacrylate, and poly-4-methyl-pentene-1.

13. An optical device according to claim 10, wherein said organic material contains an organic material having an electric conduction which is one selected from the group consisting of a π

electron conjugated polymer, a linear full π

conjugated polymer, and a non-conjugated polymer.

14. An optical device according to claim 10, wherein said organic material contains an organic material showing photochromism which is one selected from the group consisting of spirobenzopyran, fulgide, diarylethenes, and cyclophene.

15. An optical device according to claim 10, wherein said optical device is a surface emitting type device and wherein said reflector is disposed so that it reflects light from an active layer of said surface emitting type device.

16. An optical device according to claim 15, wherein said active layer is made of a second nitride semiconductor.

17. An optical device according to claim 10, wherein said optical device is a surface emitting type device in which a first reflecting portion for reflecting light from an active layer of said surface emitting type device and a second reflecting portion for reflecting light from said active layer are disposed so that they sandwich said active layer, and wherein at least one of said first reflecting portion and said second reflecting portion comprises said reflector.

18. An optical device according to claim 17, wherein said active layer is made of a third nitride semiconductor.

19. A method for manufacturing an optical device comprising a reflector for reflecting light, said reflector is formed by comprising:

forming a laminated layers in which a plurality of semiconductor layers, each of which is made of a first nitride semiconductor containing aluminum, and a plurality of etching layers, each of which is made of a second nitride semiconductor having a lower content of aluminum than said first nitride semiconductor, are alternately laminated; and

heating said laminated layers in an atmosphere containing hydrogen to etch said plurality of etching layers exposed to the end face of said laminated layers to thereby form gaps between neighboring ones of said semiconductor layers.

20. A method for manufacturing an optical device according to claim 19, wherein said atmosphere containing hydrogen is a mixed gas of hydrogen gas and at least one gas selected from the group consisting of nitrogen, ammonia, helium, argon, xenon, and neon, or a gas substantially consisting of hydrogen gas.

21. A method for manufacturing an optical device according to claim 19, wherein said first nitride semiconductor is Al_xGa_1-xN (0≦

x≦

1) and wherein said second nitride semiconductor is Al_yGa_1-yN (0≦

y<

x) or In_zGa_1-zN(0≦

z≦

1).

22. A method for manufacturing an optical device comprising a reflector for reflecting light, said reflector is formed by comprising:

forming a laminated layers in which a plurality of semiconductor layers, each of which is made of a first nitride semiconductor containing aluminum, and a plurality of etching layers, each of which is made of a second nitride semiconductor having a lower content of aluminum than said first nitride, are alternately laminated;

heating said laminated layers in an atmosphere containing hydrogen to etch said plurality of etching layers exposed to the end face of said laminated layers to thereby form gaps between neighboring ones of semiconductor layers; and

forming organic layers in said gaps.

23. A method for manufacturing an optical device according to claim 22, wherein said atmosphere containing hydrogen is a mixed gas of hydrogen gas and at least one gas selected from the group consisting of nitrogen, ammonia, helium, argon, xenon, and neon, or a gas substantially consisting of hydrogen gas.

24. A method for manufacturing an optical device according to claim 22, wherein said first nitride semiconductor is Al_xGa_1-xN(0≦

x≦

1) and wherein said second nitride semiconductor is Al_yGa_1-yN (0≦

y<

x) or In_zGa_1-zN (0≦

z≦

1).

25. A method for manufacturing a surface emitting type device in which a first reflector for reflecting light from an active layer of said surface emitting type device and a second reflector for reflecting light from said active layer are disposed to sandwich said active layer, at least one of said first reflector and said second reflector is formed by comprising:

forming a laminated layers in which a plurality of semiconductor layers, each of which is made of a first nitride semiconductor containing aluminum, and a plurality of etching layers, each of which is made of a second nitride semiconductor having a lower content of aluminum than said first nitride semiconductor, are alternately laminated; and

heating said laminated layers in an atmosphere containing hydrogen to etch said plurality of etching layers exposed to the end face of said laminated layers to thereby form gaps between neighboring ones of semiconductor layers.

26. A method for manufacturing an optical device according to claim 25, wherein said atmosphere containing hydrogen is a mixed gas of hydrogen gas and at least one gas selected from the group consisting of nitrogen, ammonia, helium, argon, xenon, and neon, or a gas substantially consisting of hydrogen gas.

27. A method for manufacturing a surface emitting type device according to claim 25, wherein said first nitride semiconductor is Al_xGa_1-xN (0≦

x≦

1) and wherein said second nitride semiconductor is Al_yGa_1-yN (0≦

y<

x) or In_zGa_1-zN(0≦

z≦

1).

29. A method for manufacturing an optical device according to claim 25, wherein said atmosphere containing hydrogen is a mixed gas of hydrogen gas and at least one gas selected from the group consisting of nitrogen, ammonia, helium, argon, xenon, and neon, or a gas substantially consisting of hydrogen gas.

28. A method for manufacturing a surface emitting type device in which a first reflector for reflecting light from an active layer of said surface emitting type device and a second reflector for reflecting light from said active layer are disposed to sandwich said active layer, at least one of said first reflector and said second reflector is formed by comprising:

forming a laminated layers in which a plurality of semiconductor layers, each of which is made of a first nitride semiconductor containing aluminum, and a plurality of etching layers, each of which is made of a second nitride semiconductor having a lower content of aluminum than said first nitride semiconductor, are alternately laminated;

heating said laminated layers in an atmosphere containing hydrogen to etch said plurality of etching layers exposed to the end face of said laminated layers to thereby form a gap between neighboring semiconductor layers; and

forming organic layers in said gaps.

30. A method for manufacturing a surface emitting type device according to claim 28, wherein said first nitride semiconductor is Al_xGa_1-xN (0≦

x≦

1) and wherein said second nitride semiconductor is Al_yGa_1-yN (0≦

y<

x) or In_zGa_1-zN(0≦

Z≦

1).