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US4424527A
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Bonding pad metallization for semiconductor devices
Assignee: McDonnell Douglas Corp
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Filing: 1981-07-31
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Granted: 1984-01-03
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Expires: 2001-07-31
Abstract
Abstract The invention is directed to a bonding pad metallization for stress sensitive semiconductor devices such as semiconductor lasers or the like. An attendant advantage is a diffusion barrier layer which inhibits the migration of conventional bonding materials such as indium solder.
Inventors
- 👤 Srinivas T. Rao
- 👤 Jeoffrey Mott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:55
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/20; H10W70/24; H01; H01S; H01S5/00; H01S5/02; H01S5/022; H01S5/023; H01S2301/00; H01S2301/17; H01S2301/173; H01S5/0233; H01S5/0234; H01S5/0235; H01S5/02355; H01S5/0237; H01S5/04; H01S5/042; H01S5/0425; H01S5/04252; H01S5/20; H01S5/22; H01S5/223; H01S5/2231; H01S5/30; H01S5/32; H01S5/323; H01S5/32308; H01S5/32316
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
69 words
A bonding pad metallization for semiconductor electronic devices comprising: a first layer of gold having a thickness of 1.5 microns or greater deposited onto said semiconductor device; a layer of nickel deposited onto said gold layer; a second layer of gold deposited onto said nickel layer, with said layer of nickel and said second layer of gold both being relatively thin as compared to said first layer of gold.
Claim 2
Dependent Claim
69 words
A bonding pad metallization for semiconductor electronic devices comprising: a first layer of gold having a thickness of 1.5 microns or greater deposited onto said semiconductor device; a layer of nickel deposited onto said gold layer; a second layer of gold deposited onto said nickel layer, with said layer of nickel and said second layer of gold both being relatively thin as compared to said first layer of gold.
Claim 3
Dependent Claim
15 words
The bonding pad metallization of claim 1 wherein said semiconductor device comprises a semiconductor laser.
Claim 4
Dependent Claim
15 words
The bonding pad metallization of claim 2 wherein said laser comprises a GaAs/GaAlAs semiconductor laser.
Claim 5
Dependent Claim
24 words
The bonding pad metallization of claim 3 wherein said first layer of gold ranges in thickness from about 1.5 microns to about 8.0 microns.
Claim 6
Dependent Claim
22 words
The bonding pad metallization of claim 4 wherein said nickel layer ranges in thickness from about 0.15 microns to about 0.5 microns.
Claim 7
Dependent Claim
25 words
The bonding pad metallization according to claim 5, wherein said second layer of gold ranges in thickness from about 0.2 microns to about 0.5 microns.
Claim 8
Dependent Claim
105 words
A bonding pad metallization for contacting the p-region of an GaAs/AlGaAs semiconductor laser comprising: a first layer of gold ranging in thickness from about 1.5 microns to about 8.0 microns deposited onto a chrome/gold contact to said p-region of the GaAs/AlGaAs laser, said first layer of gold being characterized as being in tension; a layer of amorphous nickel ranging in thickness from about 0.15 microns to about 0.5 microns deposited onto said first gold layer, said nickel layer being characterized as being in compression; a second layer of gold ranging in thickness from about 0.2 microns to about 0.5 microns deposited onto said nickel layer.
Claim 9
Dependent Claim
105 words
A bonding pad metallization for contacting the p-region of an GaAs/AlGaAs semiconductor laser comprising: a first layer of gold ranging in thickness from about 1.5 microns to about 8.0 microns deposited onto a chrome/gold contact to said p-region of the GaAs/AlGaAs laser, said first layer of gold being characterized as being in tension; a layer of amorphous nickel ranging in thickness from about 0.15 microns to about 0.5 microns deposited onto said first gold layer, said nickel layer being characterized as being in compression; a second layer of gold ranging in thickness from about 0.2 microns to about 0.5 microns deposited onto said nickel layer.
Claim 10
Dependent Claim
17 words
The bonding pad metallization of claim 7 wherein said first layer of gold comprises pulse plated gold.
Claim 11
Dependent Claim
13 words
The bonding pad metallization of claim 8 wherein said nickel comprises electroplated nickel.
Claim 12
Dependent Claim
127 words
A metallization pad for indium solder bonding a semiconductor device having a gold contact layer comprising: a pad layer of gold deposited onto the said gold contact layer, said pad layer being characterized as being in tension and having a thickness in the range from about 1.5 microns to about 8.0 microns; a nickel layer deposited onto said pad layer said nickel layer being characterized as being in compression with said nickel layer being relatively thin as compared to said gold pad layer; a bonding layer of gold deposited onto said nickel layer with said bonding layer being also relatively thinner than said pad layer; an indium bonding layer contacting said gold bonding layer whereby indium diffusion and alloying with layers is minimized by the nickel layer.
Claim 13
Dependent Claim
127 words
A metallization pad for indium solder bonding a semiconductor device having a gold contact layer comprising: a pad layer of gold deposited onto the said gold contact layer, said pad layer being characterized as being in tension and having a thickness in the range from about 1.5 microns to about 8.0 microns; a nickel layer deposited onto said pad layer said nickel layer being characterized as being in compression with said nickel layer being relatively thin as compared to said gold pad layer; a bonding layer of gold deposited onto said nickel layer with said bonding layer being also relatively thinner than said pad layer; an indium bonding layer contacting said gold bonding layer whereby indium diffusion and alloying with layers is minimized by the nickel layer.
Claim 14
Dependent Claim
22 words
The metallization pad of claim 10 wherein said gold bonding layer ranges in thickness from about 0.2 microns to about 0.5 microns.
Claim 15
Dependent Claim
21 words
The metallization pad of claim 11 wherein said nickel layer ranges in thickness from about 0.15 microns to about 0.5 microns.
Claim 16
Dependent Claim
14 words
The metallization pad of claim 12 wherein said semiconductor device comprises a GaAs/GaAlAs laser.
Claim 17
Dependent Claim
22 words
The metallization pad for claim 13 wherein said gold contact is contiguous to a contact to a p-region of the GaAs/AlGaAs laser.
Claim 18
Dependent Claim
36 words
The metallization pad of claim 10 wherein said pad layer, said nickel layer and said bonding layer extend over substantially equal areas of the semiconductor device whereby inter-layer free surfaces are minimized to minimize indium ingress.
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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) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |