Laser devices using a semipolar plane

• US 9,590,392 B1
• Filed: 10/14/2015
• Issued: 03/07/2017
• Est. Priority Date: 10/13/2011
• Status: Active Grant

• Current Assignee: Kyocera SLD Laser Incorporated (Kyocera Corporation)
• Original Assignee: Soraa Laser Diode, Inc. (Kyocera Corporation)
• Inventors: Raring, James W., Lin, You-Da, Elsass, Christiane
• Primary Examiner(s): Niu, Xinning
• Assistant Examiner(s): Vu, Vu A
• Application Number:
  US14/883,137
• Time in Patent Office: 510 Days
• Field of Search: 372/45.012
• US Class Current: 1/1
• CPC Class Codes: H01L 21/0274 Photolithographic processes
• CPC Class Codes: H01L 21/042 Changing their shape, e.g. forming recesses etching of the semiconductor body H01L21/302
• CPC Class Codes: H01L 21/28123 Lithography-related aspects, e.g. sub-lithography lengths; Isolation-related aspects, e.g. to solve problems arising at the crossing with the side of the device isolation; Planarisation aspects
• CPC Class Codes: H01L 21/302 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
• CPC Class Codes: H01L 21/311 Etching the insulating layers by chemical or physical means H01L21/31058 takes precedence
• CPC Class Codes: H01L 21/461 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
• CPC Class Codes: H01L 21/469 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques encapsulating layers H01L21/56; After-treatment of these layers
• CPC Class Codes: H01L 21/4828 Etching etching for cleaning without patterning H01L21/4835
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/0014 Measuring characteristics or properties thereof measuring techniques per se G01J, G01K, G01N, G01R
• CPC Class Codes: H01S 5/028 Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
• CPC Class Codes: H01S 5/0287 Facet reflectivity
• CPC Class Codes: H01S 5/04252 characterised by the material
• CPC Class Codes: H01S 5/2009 by using electron barrier layers
• CPC Class Codes: H01S 5/2031 characterized by special waveguide layers, e.g. asymmetric waveguide layers or defined bandgap discontinuities
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/2201 in a specific crystallographic orientation
• CPC Class Codes: H01S 5/2214 based on oxides or nitrides
• CPC Class Codes: H01S 5/320275 : semi-polar orientation
• CPC Class Codes: H01S 5/3214 : comprising materials from other groups of the periodic system than the materials of the active layer, e.g. ZnSe claddings and GaAs active layer
• CPC Class Codes: H01S 5/3216 : quantum well or superlattice cladding layers
• CPC Class Codes: H01S 5/3401 : having no PN junction, e.g. unipolar lasers, intersubband lasers, quantum cascade lasers
• CPC Class Codes: H01S 5/34333 : with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser
• CPC Class Codes: H10N 30/082 : by etching, e.g. lithography

Abstract

An optical device includes a gallium and nitrogen containing substrate comprising a surface region configured in a (20-2-1) orientation, a (30-3-1) orientation, or a (30-31) orientation, within +/−10 degrees toward c-plane and/or a-plane from the orientation. Optical devices having quantum well regions overly the surface region are also disclosed.

Claims

1. A laser device comprising:

a gallium and nitrogen containing material comprising a semipolar surface configured on a (30-3-1) orientation, a (30-31) orientation, a (20-2-1) orientation, or a (30-3-2) orientation, the semipolar surface having an offcut of the orientation;

an n-type cladding region overlying the semipolar surface;

an active region comprising at least one light emitting active layer region overlying the n-type cladding region;

the light emitting active layer region comprising a quantum well region or a double hetero-structure region;

a p-type cladding region overlying the active region;

a conductive oxide overlying the p-type cladding region;

a laser stripe region comprising at least a portion of the p-type cladding region and the conductive oxide, the laser stripe region being characterized by a cavity orientation substantially parallel to the projection of a c-direction, the laser stripe region having a first end and a second end;

a first facet having a first mirror surface provided on the first end of the laser stripe region;

a reflective coating provided on the first facet; and

a second facet having a second mirror surface provided on the second end of the laser stripe region;

wherein the laser device is configured to emit electromagnetic radiation with a peak wavelength of between 400 nm and 500 nm or between 500 nm and 560 nm.

2. The device of claim 1, wherein the offcut of the orientation is between +/−

5 degrees toward a c-plane and between +/−

10 degrees toward an a-plane; and

wherein the active region contains a plurality of quantum well regions comprising 1 to 7 quantum wells, each of the quantum wells comprising substantially InGaN;

the plurality of quantum well regions ranging in thickness from 2 nm to 5 nm or from 5 nm to 10 nm;

or wherein the active region contains a double heterostructure region;

the double heterostructure region ranging in thickness from 10 nm to about 25 nm.

3. The device of claim 1, wherein the first facet and the second facet are etched facets formed using a lithography and etching process.

4. The device of claim 1, wherein the conductive oxide comprises indium tin oxide (ITO).

5. The device of claim 1, wherein the conductive oxide comprises zinc oxide (ZnO).

6. The device of claim 1, wherein the conductive oxide comprises indium tin oxide (ITO) and is formed from an electron cyclotron resonance deposition technique.

7. The device of claim 1, wherein the conductive oxide is formed from an electron cyclotron resonance deposition technique at a process temperature below 200°

C.

8. The device of claim 1, wherein the conductive oxide is formed from an electron cyclotron resonance deposition technique at a process temperature below 200°

C., wherein the substrate contains a photoresist layer during deposition to provide a lift-off technique.

9. The device of claim 1, wherein the conductive oxide is ZnO and is formed from an electron cyclotron resonance to deposition technique.

10. A green laser device comprising:

a gallium and nitrogen containing material comprising a semipolar surface configured on a (30-3-1) orientation, a (30-31) orientation, a (20-2-1) orientation, a (20-21) orientation, or a (30-3-2) orientation, the semipolar surface having an offcut of the orientation;

an n-type cladding region overlying the semipolar surface;

an active region comprising at least one light emitting active layer region overlying the n-type cladding region;

the light emitting active layer region comprising a quantum well region or a double hetero-structure region;

a laser stripe region overlying the active region, the laser stripe region comprising conductive oxide and being characterized by a cavity orientation substantially parallel to the projection of a c-direction, the laser stripe region having a first end and a second end;

a first facet having a first mirror surface provided on the first end of the laser stripe region;

a reflective coating provided on the first facet; and

a second facet having a second mirror surface provided on the second end of the laser stripe region;

wherein the green laser device is configured to emit electromagnetic radiation with a peak wavelength of between 500 nm and 580 nm.

11. The device of claim 10, wherein the offcut of the orientation is between +/−

5 degrees toward a c-plane and between +/−

10 degrees toward an a-plane;

wherein the active region contains a plurality of quantum well regions comprising 1 to 7 quantum wells, each of the quantum wells comprising substantially InGaN;

the plurality of quantum well regions ranging in thickness from 2 nm to 5 nm or from 5 nm to 10 nm;

or wherein the active region contains a double heterostructure region;

the double heterostructure region ranging in thickness from about 10 nm to about 25 nm.

12. The device of claim 10, wherein the first facet and the second facet are etched facets formed using a lithography and etching process.

13. The device of claim 10, comprising a p-type gallium and nitrogen containing layer overlying the active region and underlying the conductive oxide region.

14. A method for fabricating a laser device, the method comprising:

providing a gallium and nitrogen containing material having a semipolar surface configured on one of either a (30-3-1) orientation, a (30-31) orientation, a (20-2-1) orientation, a (20-21) orientation, or a (30-3-2) orientation, the semipolar surface having an offcut of the orientation;

forming an n-type cladding region overlying the semipolar surface;

forming an active region comprising at least one light emitting active layer region overlying the n-type cladding region;

the light emitting active layer region comprising a quantum well region or a double hetero-structure region; and

depositing a conductive oxide overlying the active region, the conductive oxide being formed at a process temperature of less than 450°

C. to maintain a substantially crystalline characteristic of the active region to emit electromagnetic radiation within a desired electroluminescence efficiency, the conductive oxide forming at least a part of a laser stripe region, the laser stripe region being characterized by a cavity orientation substantially parallel to the projection of a c-direction, the laser stripe region having a first end and a second end;

forming a first facet having a first mirror surface on the first end of the laser stripe region;

forming a reflective coating on the first facet; and

forming a second facet having a second mirror surface on the second end of the laser stripe region;

wherein the laser device is configured to emit electromagnetic radiation with a peak wavelength of between 500 nm and 580 nm.

15. The method of claim 14, wherein the conductive oxide is selected from indium tin oxide (ITO) and zinc oxide (ZnO).

16. The method of claim 14 wherein the conductive oxide is indium tin oxide (ITO) and is formed from an electron cyclotron resonance deposition technique.

17. The method of claim 14, wherein the conductive oxide is formed from an electron cyclotron resonance deposition technique at a process temperature below 200°

C.

18. The method of claim 14, wherein the conductive oxide is formed from an electron cyclotron resonance deposition technique at a process temperature below 200°

C., wherein the substrate contains a photoresist layer during deposition to provide a lift-off technique.

19. The method of claim 14, wherein the conductive oxide is ZnO and is formed from an electron cyclotron resonance deposition technique.

20. The method of claim 14, wherein the first facet and the second facet are etched facets formed using a lithography and etching process.