US4510514A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ohmic contacts for semiconductor devices
Assignee: Nokia Bell Labs
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Filing: 1983-08-08
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Granted: 1985-04-09
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Expires: 2003-08-08
Abstract
Abstract Disclosed is an indium-containing semiconductor device which includes an ohmic contact formed by application of successive layers of Au-Sn-Cr-Au. The combination of Sn and Cr layers provides an effective barrier to the diffusion of indium to the surface of the contact so that bonding to the contact is not impeded.
Inventors
- 👤 Irfan Camlibel
- 👤 Aland K. Chin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:56
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/83; H10H20/832; H10D; H10D62/00; H10D62/80; H10D62/85; H10D64/00; H10D64/60; H10D64/62; H10F; H10F77/00; H10F77/20; H10F77/206; H10F77/241; H10W; H10W72/00; H10W72/90; H10H20/81; H10H20/822; H10H20/824; H10H20/831; H10W72/50; H10W72/531; H10W72/536; H10W72/59
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
50 words
An indium-containing semiconductor device, including an ohmic contact to a surface of the device comprising: an alloy region comprising indium, gold and tin formed in the said surface of the device; a layer comprising chromium formed over the alloy region; and a layer comprising gold formed over the chromium layer.
Claim 2
Dependent Claim
50 words
An indium-containing semiconductor device, including an ohmic contact to a surface of the device comprising: an alloy region comprising indium, gold and tin formed in the said surface of the device; a layer comprising chromium formed over the alloy region; and a layer comprising gold formed over the chromium layer.
Claim 3
Dependent Claim
19 words
The device according to claim 1 further comprising a wire bonded to the top surface of said gold layer.
Claim 4
Dependent Claim
23 words
The device according to claim 1 wherein there is less than 0.1 atomic percent indium present on the surface of the gold layer.
Claim 5
Dependent Claim
43 words
The device according to claim 1 wherein the thickness of the alloy region is within the range 400-8000 Å, the thickness of the chromium layer is within the range 1500-4000 Å and the thickness of gold layer is within the range 5000-20,000 Å.
Claim 6
Dependent Claim
26 words
The device according to claim 1 wherein the contact is provided to an n-type InP substrate which is part of an InP/InGaAsP heterostructure light emitting device.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |