US4297393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of applying thin metal deposits to a substrate
Assignee: Intersil Corp
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Filing: 1980-02-28
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Granted: 1981-10-27
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Expires: 2000-02-28
Abstract
Abstract A method of applying thin metal sensitizing deposits to the exposed silicon areas of a silicon substrate having areas of exposed silicon and silicon oxide, including the steps of immersing the silicon substrate in a basic, aqueous solution containing a metal salt of the metal to be deposited, particularly a nickel, cobalt, or platinum salt, and thereafter reducing the metal ion of the salt to the elemental metal by use of the exposed silicon as the reducing agent.
Inventors
- 👤 Richard Denning
- 👤 Mark A. Spak
- 👤 Barry Polhemus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:01
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/28
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
73 words
A method of applying thin metal sensitizing deposits from aqueous solution to the exposed silicon areas of a silicon substrate having exposed areas of silicon and silicon oxide, which comprises, immersing the silicon substrate in a basic, aqueous solution containing a metal salt of the metal to be deposited, not containing a reducing agent and reducing the metal ion by use of the exposed silicon as the reducing agent to the elemental metal.
Claim 2
Independent Claim
73 words
A method of applying thin metal sensitizing deposits from aqueous solution to the exposed silicon areas of a silicon substrate having exposed areas of silicon and silicon oxide, which comprises, immersing the silicon substrate in a basic, aqueous solution containing a metal salt of the metal to be deposited, not containing a reducing agent and reducing the metal ion by use of the exposed silicon as the reducing agent to the elemental metal.
Claim 3
Dependent Claim
13 words
The method according to claim 1 wherein sald aqueous solution contains an amine.
Claim 4
Dependent Claim
23 words
The method according to claim 2 wherein the metal salt is selected from the group consisting of salts of nickel, cobalt, and platinum.
Claim 5
Dependent Claim
18 words
The method according to claim 3 wherein the metal salt is nickel chloride and the amine is ethanolamine.
Claim 6
Dependent Claim
20 words
The method according to claim 3 wherein a metal layer is deposited onto said metal sensitizing deposits by electroless plating.
Claim 7
Dependent Claim
12 words
The method according to claim 5 wherein the plated metal is nickel.
Claim 8
Dependent Claim
32 words
The method according to claim 3 wherein the applied metal sensitizing deposits are reacted with the silicon to form metal silicide layers by heating to a temperature of between 350° C.-600° C.
Claim 9
Dependent Claim
20 words
The method according to claim 7 wherein a metal layer is deposited onto said metal silicide layers by electroless plating.
Claim 10
Dependent Claim
25 words
The method according to claim 8 wherein the plated metal layer is reacted with the silicon at a temperature of at least about 400° C.
Claim 11
Dependent Claim
12 words
The method according to claim 8 wherein the plated metal is nickel.
Claim 12
Independent Claim
74 words
A method of providing metal contacts to the exposed silicon areas of a silicon semiconductor device having portions of the silicon to be metallized exposed, which comprises, immersing the silicon device in a basic, aqueous metal salt-containing solution, not containing a reducing agent, reducing the metal ion of the solution to the elemental metal by use of the exposed silicon as the reducing agent, and electrolessly plating a metal layer onto said deposited metal.
Claim 13
Independent Claim
74 words
A method of providing metal contacts to the exposed silicon areas of a silicon semiconductor device having portions of the silicon to be metallized exposed, which comprises, immersing the silicon device in a basic, aqueous metal salt-containing solution, not containing a reducing agent, reducing the metal ion of the solution to the elemental metal by use of the exposed silicon as the reducing agent, and electrolessly plating a metal layer onto said deposited metal.
Claim 14
Dependent Claim
13 words
The method according to claim 11 wherein said aqueous solution includes an amine.
Claim 15
Dependent Claim
13 words
The method according to claim 12 wherein said metal salt is nickel chloride.
Claim 16
Dependent Claim
29 words
The method according to claim 11 wherein said electrolessly plated metal layer is silicided by heating to a temperature of at least about 400° C. in a non-oxidizing atmosphere.
Claim 17
Dependent Claim
14 words
The method according to claim 11 wherein said electrolessly plated metal layer is nickel.
Claim 18
Dependent Claim
34 words
The method according to claim 11 wherein said originally deposited elemental metal is silicided by heating in a non-oxidizing atmosphere to a temperature of from about 350° C.-600° C. prior to the electroless plating.
Claim 19
Dependent Claim
14 words
The method according to claim 16 wherein the electrolessly plated metal is phosphorus-containing nickel.
Claim 20
Dependent Claim
14 words
The method according to claim 17 wherein the silicon device is a p-n-p transistor.
Claim 21
Dependent Claim
14 words
The method according to claim 17 wherein the silicon device is an n-p-n transistor.
Claim 22
Dependent Claim
29 words
The method according to claim 19 wherein said electrolessly plated metal layer is silicided by heating to a temperature of at least about 600° C. in a non-oxidizing atmosphere.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |