US5091338A
Expired / Lapsed
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Process for forming heat resistant ohmic electrode
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1990-04-23
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Granted: 1992-02-25
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Expires: 2010-04-23
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. In addition, this invention provides an ohmic electrode forming process for compound semiconductor crystals for forming an ohmic electrode on an n-type GaAs semiconductor crystal, 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 an 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
2026-11-09 04:09
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
106 words
An ohmic electrode forming process for forming an ohmic electrode to provide an ohmic contact on an n-type GaAs semiconductor crystal, said process comprising the steps of: providing a Pd layer directly on an n-type GaAs semiconductor crystal; providing a Ge layer on the Pd layer; and annealing the Pd layer and the Ge layer by performing a rapid thermal annealing treatment wherein said layers are annealed between 3 seconds and 20 seconds at a temperature between 500° C. and 600° C. 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
106 words
An ohmic electrode forming process for forming an ohmic electrode to provide an ohmic contact on an n-type GaAs semiconductor crystal, said process comprising the steps of: providing a Pd layer directly on an n-type GaAs semiconductor crystal; providing a Ge layer on the Pd layer; and annealing the Pd layer and the Ge layer by performing a rapid thermal annealing treatment wherein said layers are annealed between 3 seconds and 20 seconds at a temperature between 500° C. and 600° C. 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
27 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 1, wherein said Pd layer and said Ge layer are formed by vacuum evaporation.
Claim 4
Dependent Claim
25 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 1, wherein said annealing step is performed in an inactive gas atmosphere.
Claim 5
Dependent Claim
61 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 1, wherein said first layer providing step comprises providing a Pd layer having a thickness between 300 Å and 1500 Å on said semiconductor crystal; said second layer providing step comprises providing a Ge layer having a thickness between 500 Å and 1500 Å on said Pd layer.
Claim 6
Dependent Claim
25 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 4, wherein said rapid thermal annealing treatment comprises a flash annealing treatment.
Claim 7
Dependent Claim
65 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 4, wherein said Pd layer is formed to have a thickness of about 760 Å, said Ge layer is formed to have a thickness of about 500 Å, and said Pd layer and said Ge layer are annealed at about 600° C. for about 10 seconds during said rapid thermal annealing treatment.
Claim 8
Dependent Claim
65 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 4, wherein said Pd layer is formed to have a thickness of about 1000 Å, said Ge layer is formed to have a thickness of about 1000 Å, and said Pd layer and said Ge layer are annealed at about 600° C. for about 10 seconds during said rapid thermal annealing treatment.
Claim 9
Dependent Claim
27 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 1, wherein said electrode continues to exhibit ohmic characteristics for at least 1,000 hours.
Claim 10
Dependent Claim
38 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 1, wherein said first layer providing step comprises providing a Pd layer having a thickness between 300 Å and 1500 Å on said semiconductor crystal.
Claim 11
Dependent Claim
38 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 1, wherein said second layer providing step comprises providing a Ge layer having a thickness between 500 Å and 1500 Å on said Pd layer.
Claim 12
Dependent Claim
97 words
An ohmic electrode forming process for forming an ohmic electrode to provide an ohmic contact on an n-type GaAs semiconductor crystal, said process comprising the steps of: providing a Pd layer directly on an n-type GaAs semiconductor crystal; providing a Ge layer on the Pd layer; and annealing the Pd layer and the Ge layer by performing a rapid thermal annealing treatment wherein said layers are annealed between 500° C. and 600° C. 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
97 words
An ohmic electrode forming process for forming an ohmic electrode to provide an ohmic contact on an n-type GaAs semiconductor crystal, said process comprising the steps of: providing a Pd layer directly on an n-type GaAs semiconductor crystal; providing a Ge layer on the Pd layer; and annealing the Pd layer and the Ge layer by performing a rapid thermal annealing treatment wherein said layers are annealed between 500° C. and 600° C. 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 14
Dependent Claim
34 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 11, wherein said first layer providing step comprises providing a Pd layer having a thickness between 300 Å and 1500 Å.
Claim 15
Dependent Claim
34 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals according to claim 11, wherein said second layer providing step comprises providing a Ge layer having a thickness between 500 Å and 1500 Å.
Claim 16
Dependent Claim
54 words
An ohmic electrode forming process for n-type GaAs semiconductor crystals, according to claim 11, wherein said first layer providing step comprises providing a Pd layer having a thickness between 300 Å and 1500 Å; and said second layer providing step comprises providing a Ge layer having a thickness between 500 Å and 1500 Å.
References Cited (Backward Citations)
No citation records indexed.
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