Patent US5027997A successfully refreshed from Google Patents.
US5027997A
Expired / Lapsed
US
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Silicon chip metallization system
Assignee: Raytheon Co
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Filing: 1990-04-05
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Granted: 1991-07-02
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Expires: 2010-04-05
Abstract
Abstract An improved silicon chip metallization system for use in attaching silicon chips to substrates. The improvement comprises providing a layer of titanium between the silicon chip backside and the layers of chrome and gold which are conventionally used as the backside metallization. The layer of titanium adjacent to the silicon chip backside reduces silicon dioxide formation during chip attachment procedures carried out in non-vacuum environments.
Inventors
- 👤 Joseph J. Bendik
- 👤 Stuart C. Billette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:17
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/50; H10W72/59
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
In a metallization system for attaching the backside of a silicon chip to a substrate, wherein said metallization system includes a layer of chrome located on the silicon chip backside and a layer of gold located on the layer of chrome, the improvement comprising a layer of titanium having a thickness of about 1000 angstroms and being located between the layer of chrome and the silicon chip backside wherein said layer of titanium limit the formation of silicon dioxide on said silicon chip to thereby provide improved attachment of said silicon chip to said substrate.
Claim 2
Dependent Claim
95 words
In a metallization system for attaching the backside of a silicon chip to a substrate, wherein said metallization system includes a layer of chrome located on the silicon chip backside and a layer of gold located on the layer of chrome, the improvement comprising a layer of titanium having a thickness of about 1000 angstroms and being located between the layer of chrome and the silicon chip backside wherein said layer of titanium limit the formation of silicon dioxide on said silicon chip to thereby provide improved attachment of said silicon chip to said substrate.
Claim 3
Dependent Claim
18 words
An improved metallization system according to claim 1 wherein the layer of chrome is about 300 angstroms thick.
Claim 4
Dependent Claim
18 words
An improved metallization system according to claim 1 wherein the layer of gold is about 4000 angstroms thick.
Claim 5
Dependent Claim
18 words
An improved metallization system according to claim 2 wherein the layer of gold is about 4000 angstroms thick.
Claim 6
Dependent Claim
98 words
In a method for attaching the backside of a silicon chip to a substrate wherein, prior to attachment, the silicon chip backside is coated with a layer of chrome onto which is coated a layer of gold, the improvement comprising the step of coating the silicon chip backside with a layer of titanium having a thickness of about 1000 angstroms, onto which is coated the layers of chrome and gold, respectively, wherein said layer of titanium limits the formation of silicon dioxide on said silicon chip to thereby improve said attachment of said silicon chip to said substrate.
Claim 7
Dependent Claim
98 words
In a method for attaching the backside of a silicon chip to a substrate wherein, prior to attachment, the silicon chip backside is coated with a layer of chrome onto which is coated a layer of gold, the improvement comprising the step of coating the silicon chip backside with a layer of titanium having a thickness of about 1000 angstroms, onto which is coated the layers of chrome and gold, respectively, wherein said layer of titanium limits the formation of silicon dioxide on said silicon chip to thereby improve said attachment of said silicon chip to said substrate.
Claim 8
Dependent Claim
23 words
An improved method according to claim 5 wherein the layer of chrome coated onto the layer of titanium is about 300 angstroms thick.
Claim 9
Dependent Claim
23 words
An improved method according to claim 5 wherein the layer of gold coated onto the layer of chrome is about 4000 angstroms thick.
Claim 10
Dependent Claim
23 words
An improved method according to claim 6 wherein the layer of gold coated onto the layer of chrome is about 4000 angstroms thick.
Claim 11
Dependent Claim
20 words
An improved method according to claim 5 including the further step of attaching said silicon chip backside to said substrate.
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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) | 1994-07-01 | 1994-12-31 | 1995-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-01 | 1998-12-31 | 1999-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-01 | 2002-12-31 | 2003-07-02 | $7700.00 | Window Closed / Lapsed |