US4366186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ohmic contact to p-type InP
Assignee: AT&T Inc
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Filing: 1979-09-27
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Granted: 1982-12-28
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Expires: 1999-09-27
Abstract
Abstract An ohmic contact to a semiconductor device comprising p-type InP is formed by sequentially depositing beryllium-gold and gold layers on InP and then heat-treating the device at a temperature less than 440 degrees C. An ohmic contact to p-type InGaAsP can be similarly formed.
Inventors
- 👤 Vassilis G. Keramidas
- 👤 Robert J. McCoy
- 👤 Henryk Temkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:45
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10D64/60; H10D64/62; H10D62/00; H10D62/80; H10D62/85
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
62 words
A method for making an ohmic contact to a semiconductor device comprising a p-type semiconductor material selected from the group consisting of InP and InGaAsP comprising the steps of: depositing beryllium-gold on said semiconductor material; depositing gold on said beryllium-gold; and heat treating said device at a temperature less than 440 degrees C. for a residence time of at least 1 minute.
Claim 2
Independent Claim
62 words
A method for making an ohmic contact to a semiconductor device comprising a p-type semiconductor material selected from the group consisting of InP and InGaAsP comprising the steps of: depositing beryllium-gold on said semiconductor material; depositing gold on said beryllium-gold; and heat treating said device at a temperature less than 440 degrees C. for a residence time of at least 1 minute.
Claim 3
Dependent Claim
19 words
A method as recited in claim 1 in which said heat treating is in an inert or reducing atmosphere.
Claim 4
Dependent Claim
15 words
A method as recited in claim 1 or 2 in which said semiconductor is InP.
Claim 5
Dependent Claim
24 words
A method as recited in claim 3 in which said beryllium-gold layer has a beryllium content, by weight, between 1 percent and 3 percent.
Claim 6
Dependent Claim
22 words
A method as recited in claim 4 in which said beryllium-gold layer is greater than 600 A and less than 1000 A.
Claim 7
Dependent Claim
17 words
A method as recited in claim 5 in which said beryllium-gold layer is approximately 800 A thick.
Claim 8
Dependent Claim
18 words
A method as recited in claim 1 in which said gold layer is at least 2100 A thick.
Claim 9
Dependent Claim
20 words
A method as recited in claim 5 in which said heat treating temperature is between 400 and 440 degrees C.
Claim 10
Dependent Claim
17 words
A method as recited in claim 8 in which said heat treating is for approximately 10 minutes.
Claim 11
Dependent Claim
34 words
A method as recited in claim 1 further comprising the step of depositing a palladium layer approximately 100 A thick above said InP layer, said palladium layer being deposited prior to said beryllium-gold layer.
Claim 12
Dependent Claim
21 words
A method as recited in claim 10 in which said heat treating is at a temperature less than 420 degrees C.
Claim 13
Dependent Claim
16 words
A method as recited in claim 11 in which said temperature is approximately 400 degrees C.
Claim 14
Dependent Claim
17 words
A method as recited in claim 12 in which said heat treating is for approximately 10 minutes.
Claim 15
Dependent Claim
18 words
A method as recited in claim 12 or 13 in which said device is a light emitting diode.
Claim 16
Dependent Claim
18 words
A method as recited in claim 5 in which said gold layer is at least 2100 Angstrom thick.
References Cited (Backward Citations)
US3215654A
Cited
US3620847A
Cited
US3850688A
Cited
US4022931A
Cited
US4011583A
Cited
US4218271A
Cited
US4258375A
Cited
US4260429A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |