US4989065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-resistant ohmic electrode
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1989-06-13
•
Granted: 1991-01-29
•
Expires: 2009-06-13
Abstract
Abstract This invention comprises a Pd layer formed on an n-type GaAs semiconductor crystals, and a Ge layer being formed on the Pd layer, characterized in that the thickness of the Pd layer is between 300 Å and 1500 Å and the thickness of the Ge layer is between 500 Å and 1500 Å. And this invention provides an ohmic electrode forming process for compound semiconductor crystals for forming an ohmic electrode on n-type GaAs semiconductor crystals, comprising a first layer forming step for forming a palladium (Pd) layer on a compound semiconductor crystal; a second layer forming step for forming a germanium layer (Ge) on the Pd layer; and a annealing step for annealing the Pd layer and the Ge layer by a rapid thermal annealing treatment. The Pd layer is formed between 300 Å and 1500 Å in the first layer forming step; the Ge layer is between 500 Å and 1500 Å in the second layer forming step; and the Pd layer and the Ge layer are heated in the annealing step for 3 seconds to 20 seconds at a temperature of 500° C. to 650° C. by a rapid thermal annealing treatment. As the rapid thermal annealing treatment, the flash annealing treatment is effective.
Inventors
- 👤 Junichi Tsuchimoto
- 👤 Tooru Yamada
- 👤 Takaya Miyano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:42
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; H10D1/474; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10D64/60; H10D64/62; H10D62/00; H10D62/80; H10D62/85; Y; Y10; Y10S; Y10S148/00; Y10S148/056; Y10S148/058
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
87 words
An ohmic electrode providing an ohmic contact, said electrode comprising palladium and germanium and said electrode being formed by providing a Pd layer having a thickness between 300 Å and 1500 Å directly onto a n-type GaAs semiconductor crystal, providing a Ge layer having a thickness between 500 Å and 1500 Å on the Pd layer, and conducting a rapid thermal annealing treatment whereby said electrode continues to exhibit ohmic characteristics when it is kept in high temperature conditions at 300° C. for at least 100 hours.
Claim 2
Dependent Claim
87 words
An ohmic electrode providing an ohmic contact, said electrode comprising palladium and germanium and said electrode being formed by providing a Pd layer having a thickness between 300 Å and 1500 Å directly onto a n-type GaAs semiconductor crystal, providing a Ge layer having a thickness between 500 Å and 1500 Å on the Pd layer, and conducting a rapid thermal annealing treatment whereby said electrode continues to exhibit ohmic characteristics when it is kept in high temperature conditions at 300° C. for at least 100 hours.
Claim 3
Dependent Claim
28 words
An ohmic electrode according to claim 1, wherein the thickness of said Pd layer is about 760 Å and that of said Ge layer is about 500 Å.
Claim 4
Dependent Claim
20 words
An ohmic electrode according to claim 1, wherein said Pd layer and said Ge layer are formed by vacuum evaporation.
Claim 5
Dependent Claim
23 words
An ohmic electrode according to claim 1, wherein said rapid thermal annealing treatment is performed by a flash annealing treatment with flash lamp.
Claim 6
Dependent Claim
28 words
An ohmic electrode according to claim 1, wherein the temperature during said annealing treatment is about 600° C. and said treatment has a duration of about 10 seconds.
Claim 7
Dependent Claim
24 words
An ohmic electrode according to claim 1, wherein said electrode maintains ohmic characteristics in a range between about -2.000 volts to about +2.000 volts.
Claim 8
Dependent Claim
87 words
An ohmic electrode providing an ohmic contact, said electrode consisting of palladium and germanium and said electrode being formed by providing a Pd layer having a thickness between 300 Å and 1500 Å on an n-type GaAs semiconductor crystal, providing a Ge layer having a thickness between 500 Å and 1500 Å on the Pd layer, and conducting a rapid thermal annealing treatment whereby said electrode continues to exhibit ohmic characteristics when it is kept in high temperature conditions at 300° C. for at least 100 hours.
Claim 9
Dependent Claim
87 words
An ohmic electrode providing an ohmic contact, said electrode consisting of palladium and germanium and said electrode being formed by providing a Pd layer having a thickness between 300 Å and 1500 Å on an n-type GaAs semiconductor crystal, providing a Ge layer having a thickness between 500 Å and 1500 Å on the Pd layer, and conducting a rapid thermal annealing treatment whereby said electrode continues to exhibit ohmic characteristics when it is kept in high temperature conditions at 300° C. for at least 100 hours.
Claim 10
Dependent Claim
20 words
An ohmic electrode according to claim 7, wherein said electrode continues to exhibit ohmic characteristics for at least 1,000 hours.
Claim 11
Dependent Claim
69 words
An ohmic electrode providing an ohmic contact, said electrode comprising palladium and germanium and said electrode being formed by providing a Pd layer directly onto an n-type GaAs semiconductor crystal, providing a Ge layer on the Pd layer, and conducting a rapid thermal annealing treatment whereby said electrode continues to exhibit ohmic characteristics when it is kept in high temperature conditions at 300° C. for at least 100 hours.
Claim 12
Dependent Claim
69 words
An ohmic electrode providing an ohmic contact, said electrode comprising palladium and germanium and said electrode being formed by providing a Pd layer directly onto an n-type GaAs semiconductor crystal, providing a Ge layer on the Pd layer, and conducting a rapid thermal annealing treatment whereby said electrode continues to exhibit ohmic characteristics when it is kept in high temperature conditions at 300° C. for at least 100 hours.
Claim 13
Dependent Claim
20 words
An ohmic electrode according to claim 9, wherein said electrode continues to exhibit ohmic characteristics for at least 1,000 hours.
Claim 14
Dependent Claim
28 words
An ohmic electrode according to claim 18, wherein the temperature during said annealing treatment is about 600° C. and said treatment has a duration of about 10 seconds.
Claim 15
Dependent Claim
87 words
An ohmic electrode providing an ohmic contact, said electrode comprising palladium and germanium and said electrode being formed by providing a Pd layer having a thickness between 300 Å and 1500 Å directly onto an n-type GaAs semiconductor crystal, providing a Ge layer having a thickness between 500 Å and 1500 Å on the Pd layer, and conducting a rapid thermal annealing treatment of said electrode wherein the temperature during said annealing treatment is about 600° C. and said treatment has a duration of about 10 seconds.
Claim 16
Dependent Claim
87 words
An ohmic electrode providing an ohmic contact, said electrode comprising palladium and germanium and said electrode being formed by providing a Pd layer having a thickness between 300 Å and 1500 Å directly onto an n-type GaAs semiconductor crystal, providing a Ge layer having a thickness between 500 Å and 1500 Å on the Pd layer, and conducting a rapid thermal annealing treatment of said electrode wherein the temperature during said annealing treatment is about 600° C. and said treatment has a duration of about 10 seconds.
References Cited (Backward Citations)
US4011583A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-28 | 1994-07-30 | 1995-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-28 | 1998-07-30 | 1999-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-28 | 2002-07-30 | 2003-01-29 | $7700.00 | Window Closed / Lapsed |