Non-uniform multiple quantum well structure

• US 9,722,139 B2
• Filed: 04/16/2013
• Issued: 08/01/2017
• Est. Priority Date: 04/16/2012
• Status: Active Grant

• Current Assignee: Sensor Electronic Technology Incorporated (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Sensor Electronic Technology Incorporated (Seoul Semiconductor Co., Ltd.)
• Inventors: Shur, Michael, Dobrinsky, Alexander, Yang, Jinwei, Shatalov, Maxim S, Gaska, Remigijus, Sun, Wenhong
• Primary Examiner(s): Lee, Cheung
• Assistant Examiner(s): Smith, Stephen C
• Application Number:
  US13/863,423
• Publication Number:
  US 20130270519A1
• Time in Patent Office: 1,568 Days
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02505 consisting of more than two layers
• CPC Class Codes: H01L 21/02507 Alternating layers, e.g. superlattice
• CPC Class Codes: H01L 21/02513 Microstructure
• CPC Class Codes: H01L 33/0066 with a substrate not being a III-V compound
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier

Abstract

A light emitting heterostructure including one or more fine structure regions is provided. The light emitting heterostructure can include a plurality of barriers alternating with a plurality of quantum wells. One or more of the barriers and/or quantum wells includes a fine structure region. The fine structure region includes a plurality of subscale features arranged in at least one of: a growth or a lateral direction.

Claims

1. A device comprising:

a semiconductor structure including an active region, wherein the active region comprises a light emitting heterostructure including;

a plurality of barriers alternating with a plurality of quantum wells, wherein at least one of;

a barrier in the plurality of barriers or a quantum well in the plurality of quantum wells includes a plurality of regions including a fine structure region located only in an outer portion of the at least one of;

the barrier or the quantum well, wherein the fine structure region includes a plurality of subscale features arranged in a growth direction, wherein the plurality of subscale features includes a plurality of subscale barriers alternating with a plurality of subscale quantum wells, and wherein the plurality of subscale barriers include subscale barriers of a plurality of distinct heights differing from each other.

2. The device of claim 1, wherein the fine structure region further includes a first plurality of laterally discrete subscale features of varying composition, wherein each of the first plurality of laterally discrete subscale features has a lateral size in a range between three nanometers and three micrometers, and wherein the fine structure region is adjacent to at least one of:

a barrier in the plurality of barriers or a quantum well in the plurality of quantum wells having a substantially contiguous lateral composition.

3. The device of claim 2, wherein the fine structure region further includes a second plurality of laterally discrete sub-regions of varying composition located on an immediately adjacent growth plane to a growth plane for the first plurality of laterally discrete sub-regions, and wherein the second plurality of laterally discrete sub-regions are laterally staggered from the first plurality of laterally discrete sub-regions.

4. The device of claim 1, wherein the fine structure region includes a plurality of subscale layers having alternating compressive and tensile stresses.

5. The device of claim 1, wherein the plurality of regions further include a second fine structure region located only in a second outer portion of the at least one of:

the barrier or the quantum well.

6. The device of claim 1, wherein the subscale quantum wells include quantum wells of differing depths.

7. The device of claim 1, wherein the fine structure region is in the barrier in the plurality of barriers adjacent to a barrier-quantum well heterojunction, and wherein the plurality of distinct heights decrease toward the heterojunction.

8. The device of claim 1, wherein the fine structure region is located in the barrier in the plurality of barriers, and wherein a height of each of the subscale barriers is no higher than a barrier height of the barrier in the plurality of barriers.

9. The device of claim 1, wherein the fine structure region is located in the quantum well in the plurality of quantum wells, and wherein a height of each of the subscale barriers is higher than a quantum well depth of the quantum well in the plurality of quantum wells and is lower than each of a set of barriers adjacent to the quantum well.

10. The device of claim 1, wherein at least one of the subscale features is laterally non-uniform.

11. A device comprising:

a group III nitride semiconductor structure including an active region, wherein the active region comprises a light emitting heterostructure including;

a plurality of barriers alternating with a plurality of quantum wells, wherein at least one of;

a barrier in the plurality of barriers or a quantum well in the plurality of quantum wells includes a plurality of regions including a fine structure region located only in an outer portion of the at least one of;

the barrier or the quantum well, and wherein the fine structure region includes a plurality of subscale layers having alternating compressive and tensile stresses, wherein the compressive and tensile stresses in the plurality of subscale layers decrease in a direction toward a barrier-quantum well heterojunction adjacent to the outer portion.

12. The device of claim 11, wherein the semiconductor structure is composed of aluminum gallium nitride materials.

13. The device of claim 12, wherein the barrier in the plurality of barriers includes the fine structure region, and wherein at least one of the plurality of subscale layers has a higher gallium content than a gallium content of the barrier.

14. The device of claim 12, wherein the quantum well in the plurality of quantum wells includes the fine structure region, and wherein at least one of the plurality of subscale layers have a higher aluminum content than an aluminum content of the quantum well.

15. The device of claim 12, wherein the fine structure region further includes a plurality of subscale features arranged in a lateral direction, wherein each of the plurality of subscale features has a lateral size in a range between three nanometers and three micrometers.

16. A method comprising:

forming an active region of a semiconductor structure, wherein the active region comprises a light emitting heterostructure, the forming including;

forming a plurality of barriers alternating with a plurality of quantum wells, wherein forming at least one of;

a barrier in the plurality of barriers or a quantum well in the plurality of quantum wells includes forming a plurality of regions including a fine structure region located only in an outer portion of the at least one of;

the barrier in the plurality of barriers or the quantum well in the plurality of quantum wells, and wherein the fine structure region includes a plurality of subscale features arranged in a growth direction, wherein the plurality of subscale features includes a plurality of subscale barriers alternating with a plurality of subscale quantum wells, and wherein the plurality of subscale barriers includes subscale barriers of a plurality of distinct heights differing from each other.

17. The method of claim 16, wherein the forming the fine structure region includes modulating a V/III ratio during epitaxial growth of the at least one of:

the barrier in the plurality of barriers or the quantum well in the plurality of quantum wells.

18. The method of claim 16, wherein the forming the fine structure region includes modulating a growth temperature during epitaxial growth of the at least one of:

the barrier in the plurality of barriers or the quantum well in the plurality of quantum wells.

19. The method of claim 16, wherein the forming the fine structure region includes time modulating of at least one of:

a V/III ratio or a growth temperature during epitaxial growth of the at least one of;

the barrier in the plurality of barriers or the quantum well in the plurality of quantum wells to form a fine scale superlattice structure.

20. The method of claim 16, wherein the forming the fine structure region includes pulsing epitaxial growth through controlling timing patterns of switch-on and switch-off metalorganic precursors and a nitrogen precursor.