US4395727A
Expired / Lapsed
US
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Barrier-free, low-resistant electrical contact on III-V semiconductor material
Assignee: Siemens AG
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Filing: 1981-03-17
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Granted: 1983-07-26
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Expires: 2001-03-17
Abstract
Abstract A contact structure on indium-containing III-V semiconductor material is comprised of a four layer sequence consisting of an indium layer in direct contact with the semiconductor material, a zinc layer in contact with the indium layer, a chromium-nickel or chromium or palladium or platinum layer in contact with the zinc layer and a gold layer for external contacting with a lead. An exemplary embodiment of such contact structure exhibits specific contact resistance ranging between about 10 -4 and 10 -5 ohm· cm 2 .
Inventors
- 👤 Christl Lauterbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:38
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/62; H10D64/01; H10D64/011; H10D64/0116; H10W; H10W20/00; H10W20/40; H10W72/00; H10W72/01; H10W72/019; H10D62/00; H10D62/80; H10D62/85; H10W72/50; H10W72/531; H10W72/536; H10W72/59; H10W72/851; H10W72/874; H10W72/884; H10W72/90; H10W72/921; H10W72/923; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
153 words
A barrier-free, low-resistance contact structure for semiconductor components based on indium-containing III-V semiconductor material, comprising: a plurality of layers positioned on one another in a layer sequence on a select area of said semiconductor component, with a first layer of said sequence being in direct contact with said semiconductor material and consisting of indium; with a second layer of said sequence being in direct contact with said first layer and being composed of a material having a p-doping effect in said semiconductor material; with an uppermost layer of said sequence being composed of a metal available for external contact of said semiconductor component; said layer sequence being subjected to a common thermal treatment; and with a third layer being positioned in the layer sequence between said second layer and said uppermost layer, said third layer being composed of a material selected from the group consisting of platinum, palladium, chromium and a chromium-nickel alloy.
Claim 2
Dependent Claim
153 words
A barrier-free, low-resistance contact structure for semiconductor components based on indium-containing III-V semiconductor material, comprising: a plurality of layers positioned on one another in a layer sequence on a select area of said semiconductor component, with a first layer of said sequence being in direct contact with said semiconductor material and consisting of indium; with a second layer of said sequence being in direct contact with said first layer and being composed of a material having a p-doping effect in said semiconductor material; with an uppermost layer of said sequence being composed of a metal available for external contact of said semiconductor component; said layer sequence being subjected to a common thermal treatment; and with a third layer being positioned in the layer sequence between said second layer and said uppermost layer, said third layer being composed of a material selected from the group consisting of platinum, palladium, chromium and a chromium-nickel alloy.
Claim 3
Dependent Claim
17 words
A contact structure as defined in claim 1 wherein the indium of said first layer is vapor-deposited.
Claim 4
Dependent Claim
24 words
A contact structure as defined in claim 2 wherein the indium layer is deposited in a thickness ranging from about 20 through 50 nm.
Claim 5
Dependent Claim
27 words
A contact structure as defined in claim 1 wherein the p-doping material forming said second layer is selected from the group consisting of zinc, beryllium and cadmium.
Claim 6
Dependent Claim
24 words
A contact structure as defined in claim 4 wherein said second layer is applied in a thickness ranging between about 10 through 30 nm.
Claim 7
Dependent Claim
31 words
A contact structure as defined in claim 1 wherein said third layer is composed of a chromium-nickel alloy having a composition which, with crucible evaporation is obtained from a nickel-50-chromium-50 alloy.
Claim 8
Dependent Claim
25 words
A contact structure as defined in claim 6 wherein the thickness of said third layer is in a range of about 5 through 20 nm.
Claim 9
Dependent Claim
27 words
A contact structure as defined in claim 1 wherein said uppermost layer is gold and is applied in a thickness ranging from about 300 to 600 nm.
Claim 10
Dependent Claim
48 words
A contact structure as defined in claim 1 wherein said first layer consists of approximately 30 nm vapor-deposited indium, said second layer consists of approximately 20 nm zinc said third layer consists of approximately 10 nm chromium-nickel alloy and said uppermost layer consists of 500 nm vapor-deposited gold.
Claim 11
Dependent Claim
40 words
A contact structure as defined in claim 1 wherein said common thermal treatment comprises heating said layer sequence to a temperature ranging between about 350° C. and 450° C. over a time duration ranging between about 40 through 90 seconds.
References Cited (Backward Citations)
US4017332A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |