US6201262B1
Expired / Lapsed
US
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Group III nitride photonic devices on silicon carbide substrates with conductive buffer interlay structure
Assignee: Wolfspeed Inc
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Filing: 1997-10-07
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Granted: 2001-03-13
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Expires: 2017-10-07
Abstract
Abstract An optoelectronic device with a Group III Nitride active layer is disclosed that comprises a silicon carbide substrate; an optoelectronic diode with a Group III nitride active layer; a buffer structure selected from the group consisting of gallium nitride and indium gallium nitride between the silicon carbide substrate and the optoelectronic diode; and a stress-absorbing structure comprising a plurality of predetermined stress-relieving areas within the crystal structure of the buffer structure, so that stress-induced cracking that occurs in the buffer structure occurs at predetermined areas rather than elsewhere in the buffer structure.
Inventors
- 👤 John Adam Edmond
- 👤 Hua-Shuang Kong
- 👤 Kathleen Marie Doverspike
- 👤 Michelle Turner Leonard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:21
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H10H20/0133; H10H20/01335; H10P; H10P14/00; H10P14/20; H10P14/27; H10P14/271; H10P14/272; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2904; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3216; H10P14/3242; H10P14/3256; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3416
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
117 words
An optoelectronic device with a Group III Nitride active layer, said device comprising: a conductive silicon carbide substrate; an ohmic contact to said substrate; an optoelectronic diode with a Group III nitride active layer; a buffer structure selected from the group consisting of gallium nitride and indium gallium nitride between said silicon carbide substrate and said optoelectronic diode; and a stress-absorbing structure comprising a predetermined grid pattern of grooves in the surface of said silicon carbide substrate and a corresponding grid pattern of stress-absorbing areas propagated into said buffer from said grooves in said substrate, so that stress-induced cracking that occurs in said buffer structure occurs at said predetermined areas rather than elsewhere in said buffer structure.
Claim 2
Dependent Claim
117 words
An optoelectronic device with a Group III Nitride active layer, said device comprising: a conductive silicon carbide substrate; an ohmic contact to said substrate; an optoelectronic diode with a Group III nitride active layer; a buffer structure selected from the group consisting of gallium nitride and indium gallium nitride between said silicon carbide substrate and said optoelectronic diode; and a stress-absorbing structure comprising a predetermined grid pattern of grooves in the surface of said silicon carbide substrate and a corresponding grid pattern of stress-absorbing areas propagated into said buffer from said grooves in said substrate, so that stress-induced cracking that occurs in said buffer structure occurs at said predetermined areas rather than elsewhere in said buffer structure.
Claim 3
Dependent Claim
13 words
An optoelectronic device according to claim 1 wherein said buffer structure is conductive.
Claim 4
Dependent Claim
12 words
An optoelectronic device according to claim 1 comprising a light emitting diode.
Claim 5
Dependent Claim
13 words
A pixel that incorporates a light emitting diode according to claim 3 .
Claim 6
Dependent Claim
13 words
A display that incorporates a plurality of pixels according to claim 4 .
Claim 7
Dependent Claim
11 words
An optoelectronic device according to claim 1 comprising a laser diode.
Claim 8
Dependent Claim
18 words
An optoelectronic device according to claim 1 wherein said grid defines squares of about 250 microns per side.
Claim 9
Dependent Claim
18 words
An optoelectronic device according to claim 1 wherein said grid defines rectangles of about 250 by 500 microns.
Claim 10
Dependent Claim
30 words
An optoelectronic device according to claim 1 wherein said diode is selected from the group consisting of p-n homojunctions, p-n single and double heterojunctions, and p-n quantum junction well structures.
Claim 11
Dependent Claim
32 words
An optoelectronic device according to claim 1 wherein said silicon carbide substrate has a polytype selected from the group consisting of the 3 C, 4 H, 6 H, and 15 R polytypes.
Claim 12
Dependent Claim
17 words
An optoelectronic device according to claim 1 wherein said Group III nitride active layer comprises gallium nitride.
Claim 13
Dependent Claim
16 words
An optoelectronic device according to claim 1 wherein said Group III nitride comprises indium gallium nitride.
Claim 14
Dependent Claim
98 words
A wafer precursor for Group III nitride devices, said precursor wafer comprising: a silicon carbide substrate wafer; a buffer layer on said substrate and selected from the group consisting of gallium nitride and indium gallium nitride; and a stress-absorbing structure comprising a predetermined grid pattern of grooves in the surface of said silicon carbide substrate wafer and a corresponding grid pattern of stress absorbing areas propagated into said buffer from said grooves in said substrate, so that stress induced cracking that occurs in said buffer layer occurs at said predetermined areas rather than elsewhere in said buffer structure.
Claim 15
Dependent Claim
98 words
A wafer precursor for Group III nitride devices, said precursor wafer comprising: a silicon carbide substrate wafer; a buffer layer on said substrate and selected from the group consisting of gallium nitride and indium gallium nitride; and a stress-absorbing structure comprising a predetermined grid pattern of grooves in the surface of said silicon carbide substrate wafer and a corresponding grid pattern of stress absorbing areas propagated into said buffer from said grooves in said substrate, so that stress induced cracking that occurs in said buffer layer occurs at said predetermined areas rather than elsewhere in said buffer structure.
Claim 16
Dependent Claim
18 words
A wafer precursor according to claim 13 wherein said grid defines squares of about 250 microns per side.
Claim 17
Dependent Claim
16 words
A wafer precursor according to claim 13 wherein said grid defines rectangles of about 250×500 microns.
Claim 18
Dependent Claim
32 words
A wafer precursor according to claim 13 wherein said silicon carbide substrate has a polytype selected from the group consisting of the 3 C, 4 H, 6 H, and 15 R polytypes.
References Cited (Backward Citations)
US4396929A
Cited
US4865685A
Cited
US4981551A
Cited
EP0352472A2
Cited
WO1990010950A1
Cited
US5043773A
Cited
US5578839A
Cited
JPH06326416A
Cited
US5432808A
Cited
US5393993A
Cited
US5523589A
Cited
US5592501A
Cited
WO1996024167A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-12 | 2004-09-11 | 2005-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-12 | 2008-09-11 | 2009-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-12 | 2012-09-11 | 2013-03-13 | $7700.00 | Window Closed / Lapsed |