Low voltage laser diodes on {20-21} gallium and nitrogen containing substrates

• US 9,853,420 B2
• Filed: 11/29/2016
• Issued: 12/26/2017
• Est. Priority Date: 09/17/2009
• Status: Active Grant

• Current Assignee: Kyocera SLD Laser Incorporated (Kyocera Corporation)
• Original Assignee: Soraa Laser Diode, Inc. (Kyocera Corporation)
• Inventors: Raring, James W., Schmidt, Mathew, Poblenz, Christiane
• Primary Examiner(s): VAN ROY, TOD THOMAS
• Application Number:
  US15/363,756
• Publication Number:
  US 20170331255A1
• Time in Patent Office: 392 Days
• Field of Search: 372 44011, 372 4501
• CPC Class Codes: B28D 5/0011 with preliminary treatment, e.g. weakening by scoring
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/467 using masks
• CPC Class Codes: H01S 5/0014 Measuring characteristics or properties thereof measuring techniques per se G01J, G01K, G01N, G01R
• CPC Class Codes: H01S 5/0202 Cleaving
• CPC Class Codes: H01S 5/028 Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
• CPC Class Codes: H01S 5/2009 by using electron barrier layers
• CPC Class Codes: H01S 5/2201 in a specific crystallographic orientation
• CPC Class Codes: H01S 5/227 Buried mesa structure ; Striped active layer
• CPC Class Codes: H01S 5/3202 grown on specifically orientated substrates, or using orientation dependent growth
• CPC Class Codes: H01S 5/32025 non-polar orientation
• CPC Class Codes: H01S 5/320275 semi-polar orientation
• CPC Class Codes: H01S 5/3213 asymmetric clading layers
• CPC Class Codes: H01S 5/3407 characterised by special barrier layers
• 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: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

Claims

1. A laser diode device comprising:

a gallium and nitrogen containing material including a {20-21} crystalline surface region orientation;

an n-type cladding material overlying the gallium and nitrogen containing material, the n-type cladding material being substantially free from an aluminum bearing material;

an active region comprising at least three quantum wells and a plurality of barrier layers, each of the quantum wells having a thickness of 1 nm and greater, and each of the plurality of barrier layers having a thickness ranging from 1 nm to less than 3 nm, each adjacent pair of the quantum wells separated by one of the plurality of barrier layers;

a p-type cladding material overlying the active region, the p-type cladding material being free from AlGaN;

a p-type material overlying the p-type cladding material;

a laser stripe region overlying the crystalline surface region, the laser stripe region being aligned substantially in a projection of the c-direction, the laser stripe region comprising a first end and a second end;

a first facet formed on the first end; and

a second facet formed on the second end.

2. The device of claim 1 wherein the active region comprises at least six quantum well regions.

3. The device of claim 1 wherein the active region is configured operably for a forward voltage of less than 7v for an output power of 60 mW and greater.

4. The device of claim 1 wherein each of the plurality of barrier layers is at least about 2.5 nm in thickness.

5. The device of claim 1 wherein each of the plurality of barrier layers is at least about 1.5 nm to about 2.5 nm in thickness.

6. The device of claim 1 wherein the {20-21} crystalline surface region is off-cut less than less than +/−

10 deg towards a c-plane and/or an a-plane.

7. The device of claim 1 wherein one or more of the plurality of barrier layers is made of a material selected from GaN, InGaN, AlGaN, or InAlGaN.

8. The device of claim 1 wherein each of the quantum wells comprises at least InGaN.

9. The device of claim 1 wherein each of the plurality of barrier layers is substantially free from a dopant species.

10. A laser diode device comprising:

a gallium and nitrogen containing material including a {20-21} crystalline surface region orientation;

an n-type cladding material overlying the gallium and nitrogen containing material, the n-type cladding material being substantially free from an aluminum bearing material;

an active region comprising at least three quantum wells and a plurality of barrier layers, each of the quantum wells having a thickness of 1 nm and greater, and each of the plurality of barrier layers having a p-type characteristic and a thickness ranging from 1 nm to less than 3 nm, each adjacent pair of the quantum wells separated by one of the plurality of barrier layers;

a p-type cladding material overlying the active region, the p-type cladding material being substantially free from AlGaN; and

a p-type material overlying the p-type cladding material;

a laser stripe region overlying the crystalline surface region, the laser stripe region being aligned substantially in a projection of the c-direction, the laser stripe region comprising a first end and a second end;

a first facet formed on the first end; and

a second facet formed on the second end.

11. The device of claim 10 wherein the active region comprises at least six quantum well regions.

12. The device of claim 10 wherein the active region is configured operably for a forward voltage of less than 7v for an output power of 60 mW and greater.

13. The device of claim 10 wherein each of the plurality of barrier layers is at least about 2.5 nm in thickness.

14. The device of claim 10 wherein each of the plurality of barrier layers is at least about 1.5 nm to about 2.5 nm in thickness.

15. The device of claim 10 wherein the {20-21} crystalline surface region is off-cut less than less than +/−

8 deg towards a c-plane and/or an a-plane.

16. The device of claim 10 further comprising an electron blocking region between the active region and the p-type cladding material.

17. The device of claim 10 wherein one or more of the plurality of barrier layers is made of a material selected from GaN, InGaN, AlGaN, or InAlGaN.

18. The device of claim 10 wherein each of the quantum wells comprises at least InGaN.

19. The device of claim 10 wherein the p-type impurity characteristic comprising a magnesium species.

20. A laser diode device comprising:

a gallium and nitrogen containing material including a {20-21} crystalline surface region orientation;

an n-type cladding material overlying the gallium and nitrogen containing material

an active region comprising at least three quantum wells and a plurality of barrier layers, each of the quantum wells having a thickness of 1 nm and greater, and each of the plurality of barrier layers having a thickness ranging from 1 nm to less than 3 nm, each adjacent pair of the quantum wells separated by one of the plurality of barrier layers;

a p-type cladding material overlying the active region, the p-type cladding material being free from AlGaN;

a p-type material overlying the p-type cladding material;

a laser stripe region overlying the crystalline surface region, the laser stripe region being aligned substantially in a projection of the c-direction, the laser stripe region comprising a first end and a second end;

a first facet formed on the first end; and

a second facet formed on the second end, wherein the active region is configured operably for a forward voltage of less than 7V for an output power of 60 mW and greater.