Superluminescent edge emitting device with apparent vertical light emission and method of making

• US 5,498,883 A
• Filed: 10/03/1994
• Issued: 03/12/1996
• Est. Priority Date: 08/05/1992
• Status: Expired due to Fees

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ackley, Donald E., Lebby, Michael S.
• Primary Examiner(s): Meier, Stephen D.
• Application Number:
  US08/317,110
• Time in Patent Office: 526 Days
• Field of Search: 257/95, 257/98
• US Class Current: 257/95
• CPC Class Codes: H01L 33/0045 the devices being superluminescent diodes
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/465 with a resonant cavity structure

Abstract

A superluminescent edge emitting device is fabricated to have apparent vertical light emission. The superluminescent device is comprised of a semiconductor supporting structure having a major surface. A light emitting portion is formed above a first portion of the major surface, wherein the light emitting portion is configured in a substantially circular shape to suppress lasing and has sidewalls, and wherein light is emitted from the sidewalls of the light emitting portion. An non-emitting portion is formed above a second portion of the major surface and adjacent to the light emitting portion, wherein the non-emitting portion has sidewalls, and wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion are configured to direct the light emitted from the light emitting portion substantially perpendicular to the major surface.

Claims

1. A superluminescent light emitting device, comprising:

a semiconductor supporting structure comprised of a first mirror stack comprised of a plurality of layers of semiconductor materials having matching crystal structures having a major surface;

a light emitting portion formed above a first portion of the major surface, wherein the light emitting portion is comprised of an active layer comprised of at least one light emitting region formed above a portion of the first mirror stack and a second mirror stack comprised of a plurality of layers of semiconductor materials having matching crystal structures formed above the active layer, and is configured in a substantially circular shape to suppress lasing and has sidewalls, and wherein a light is emitted from the sidewalls of the light emitting portion;

a non-emitting portion formed above a second portion of the major surface and adjacent to the light emitting portion, wherein the non-emitting portion has sidewalls, and wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion are configured to direct the light emitted from the light emitting portion substantially perpendicular to the major surface.

2. The superluminescent light emitting device of claim 1, wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion form an acute angle.

3. The superluminescent light emitting device of claim 1, wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion form an oblique angle.

4. The superluminescent light emitting device of claim 1, wherein the sidewalls of the non-emitting portion are at an angle of approximately 0°

from the major surface and the sidewalls of the light emitting portion at an angle of approximately 135°

from the major surface.

5. The superluminescent light emitting device of claim 1, wherein the sidewalls of the light emitting portion are at an angle of approximately 135°

from the major surface and the sidewalls of the non-emitting portion are at an angle of approximately 45°

from the major surface.

6. The superluminescent light emitting device of claim 1, wherein the sidewalls of the light emitting portion are at an angle of approximately 90°

and the sidewalls of the non-emitting portion are at an angle of approximately 45°

from the major surface.

7. The superluminescent light emitting device of claim 1, further comprised of a reflective layer formed on the sidewalls of the non-emitting portion.

8. The superluminescent light emitting device of claim 7, wherein the reflective layer is comprised of a dielectric stack.

9. The superluminescent light emitting device of claim 1, further comprising an anti-reflective layer formed on the sidewalls of the light emitting portion.

10. The superluminescent light emitting device of claim 1, wherein the sidewalls of the non-emitting portion are curved to better focus the light substantially perpendicular to the major surface.

11. The superluminescent light emitting device of claim 1 wherein the first mirror stack and the second mirror stack are comprised of aluminum arsenide and gallium arsenide.

12. The superluminescent light emitting device of claim 1, wherein the semiconductor supporting structure is comprised of n-type gallium arsenide.

13. The superluminescent light emitting device of claim 1, wherein the light emitting portion is approximately 2-20 microns in diameter.

14. A superluminescent light emitting device, comprising:

a semiconductor supporting structure having a major surface;

a light emitting portion having sidewalls and a substantially circular configuration to suppress lasing formed above a portion of the semiconductor supporting structure, wherein the light emitting portion is comprised of a first mirror stack comprised of a plurality of layers of semiconductor materials having matching crystal structures, an active layer comprised of at least one light emitting region, and a second mirror stack comprised of a plurality of layers of semiconductor materials having matching crystal structures, formed above the active layer, wherein the combined reflectivities of the first and second mirror stacks are selected such that a light is emitted in the superluminescent operating mode from the sidewall of the active layer; and

a non-emitting portion having sidewalls formed on the semiconductor supporting structure, wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion are configured to direct the light emitted from the light emitting portion substantially perpendicular to the major surface.

15. The superluminescent light emitting device of claim 14, wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion form an acute angle.

16. The superluminescent light emitting device of claim 14, wherein the sidewalls of the light emitting portion and the sidewalls of the non-emitting portion form an oblique angle.

17. The superluminescent light emitting device of claim 14, wherein the sidewalls of the non-emitting portion are at an angle of approximately 0°

from the major surface and the sidewalls of the light emitting portion at an angle of approximately 135°

from the major surface.

18. The superluminescent light emitting device of claim 14, wherein the sidewalls of the light emitting portion are at an angle of approximately 135°

from the major surface and the sidewalls of the non-emitting portion are at an angle of approximately 45°

from the major surface.

19. The superluminescent light emitting device of claim 14, wherein the sidewalls of the light emitting portion are at an angle of approximately 90°

and the sidewalls of the non-emitting portion are at an angle of approximately 45°

from the major surface.

20. The superluminescent light emitting device of claim 14, further comprised of a reflective layer formed on the sidewalls of the non-emitting portion.

21. The superluminescent light emitting device of claim 20, wherein the reflective layer is comprised of a dielectric stack.

22. The superluminescent light emitting device of claim 14, further comprising an anti-reflective layer formed on the sidewalls of the light emitting portion.

23. The superluminescent light emitting device of claim 14, wherein the sidewalls of the non-emitting portion are curved to better focus the light substantially perpendicular to the major surface.

24. The superluminescent light emitting device of claim 14, wherein the semiconductor supporting structure is comprised of n-type gallium arsenide.

25. The superluminescent light emitting device of claim 14, wherein the light emitting portion is approximately 2-20 microns in diameter.