US3965279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ohmic contacts for group III-V n-type semiconductors
Assignee: AT&T Inc
•
Filing: 1974-09-03
•
Granted: 1976-06-22
•
Expires: 1994-09-03
Abstract
Abstract A metallization scheme for providing an ohmic contact to n-type III-V semiconductors is described. A metallurgical combination including germanium and palladium is formed on the semiconductor surface either in the form of an alloy or discrete layers. The structure is then heated so that the metallic and semiconductor components interdiffuse to establish the ohmic contact without melting of the metal. One advantage of such a solid state process is the high degree of dimensional control of the contact which is attainable.
Inventors
- 👤 Hyman Joseph Levinstein
- 👤 Ashok Kumar Sinha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:48
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/85; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10D64/60; H10D64/62; H10P; H10P14/00; H10P14/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
94 words
A method of forming an ohmic contact on a III-V n-type semiconductor material comprising the steps of forming a metal film on the surface of the semiconductor comprising a first layer comprising germanium and a second layer comprising palladium over the first layer, and heating the resulting structure at a temperature and for a time sufficient to react said metal film with said semiconductor without melting said metal film so that an ohmic contact is formed at the semiconductor surface, the relative thicknesses of the two layers being such that during the heating the
Claim 2
Independent Claim
94 words
A method of forming an ohmic contact on a III-V n-type semiconductor material comprising the steps of forming a metal film on the surface of the semiconductor comprising a first layer comprising germanium and a second layer comprising palladium over the first layer, and heating the resulting structure at a temperature and for a time sufficient to react said metal film with said semiconductor without melting said metal film so that an ohmic contact is formed at the semiconductor surface, the relative thicknesses of the two layers being such that during the heating the
Claim 3
Dependent Claim
29 words
The method according to claim 1 wherein the thickness of the first layer is within the range 100 - 1,000 A and the thickness of the second layer is
Claim 4
Dependent Claim
22 words
The method according to claim 1 wherein the structure is heated to a temperature within the range 200°-700°C for a period within
Claim 5
Dependent Claim
22 words
The method according to claim 1 wherein the structure is heated to a temperature within the range 300°-550°C for a period within
Claim 6
Dependent Claim
24 words
The method according to claim 1 wherein the structure is heated until the metal film exhibits a contact resistivity of less than 10.sup. -3
Claim 7
Dependent Claim
10 words
The method according to claim 1 wherein the semiconductor material
Claim 8
Dependent Claim
10 words
The method according to claim 1 wherein the semiconductor material
Claim 9
Dependent Claim
10 words
The method according to claim 1 wherein the semiconductor material
Claim 10
Dependent Claim
10 words
The method according to claim 1 wherein the semiconductor material
Claim 11
Independent Claim
117 words
A method of forming an ohmic contact on an n-type semiconductor material which comprises Ga and As comprising the steps of forming a metal film comprising a first layer comprising germanium on the semiconductor surface and a second layer comprising palladium over the first layer, and heating the resulting structure to a temperature in the range 200°-700°C for a period within the range 5 min. - 24 hours so as to react said metal film with said semiconductor without melting of said film so that an ohmic contact is formed at the semiconductor surface, the relative thicknesses of the two layers being such that during the heating the second layer diffuses through the first layer to the
Claim 12
Independent Claim
117 words
A method of forming an ohmic contact on an n-type semiconductor material which comprises Ga and As comprising the steps of forming a metal film comprising a first layer comprising germanium on the semiconductor surface and a second layer comprising palladium over the first layer, and heating the resulting structure to a temperature in the range 200°-700°C for a period within the range 5 min. - 24 hours so as to react said metal film with said semiconductor without melting of said film so that an ohmic contact is formed at the semiconductor surface, the relative thicknesses of the two layers being such that during the heating the second layer diffuses through the first layer to the
Claim 13
Dependent Claim
23 words
The method according to claim 10 wherein the structure is heated to a temperature within the range 300°-550°C for a period of time
Claim 14
Dependent Claim
10 words
The method according to claim 10 wherein the semiconductor material
Claim 15
Dependent Claim
27 words
The method according to claim 10 wherein the thickness of the first layer is within the range 100 - 1,000 A and the thickness of the second
Claim 16
Independent Claim
65 words
A method of forming an ohmic contact on a III-V n-type semiconductor material comprising the steps of forming metallization by depositing an alloy comprising approximately equal amounts of germanium and palladium on the surface of the semiconductor, and heating the resulting structure at a temperature and for a time sufficient to react said metallization with said semiconductor without melting said metallization so that an ohmic
Claim 17
Independent Claim
65 words
A method of forming an ohmic contact on a III-V n-type semiconductor material comprising the steps of forming metallization by depositing an alloy comprising approximately equal amounts of germanium and palladium on the surface of the semiconductor, and heating the resulting structure at a temperature and for a time sufficient to react said metallization with said semiconductor without melting said metallization so that an ohmic
Claim 18
Dependent Claim
31 words
The method according to claim 14 wherein the structure is heated to a temperature within the range 300°-550°C for a period of time within the range 10 min - 3 hours.
References Cited (Backward Citations)
US3231421A
Cited
US3239376A
Cited
US3468659A
Cited
US3523222A
Cited
US3518749A
Cited
US3567508A
Cited
US3686539A
Cited
US3684930A
Cited
US3728785A
Cited
US3890699A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |