Patent US4946376A successfully refreshed from Google Patents.
US4946376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backside metallization scheme for semiconductor devices
Assignee: Semiconductor Components Industries LLC
•
Filing: 1989-04-06
•
Granted: 1990-08-07
•
Expires: 2009-04-06
Abstract
Abstract A backside metalization scheme for semiconductor devices includes a vanadium layer disposed on the backside of a wafer and a silver layer disposed on the vanadium layer. An optional intermediate layer comprising either a mixture of vanadium and silver or nickel may be disposed between the vanadium layer and the silver layer. The vanadium layer exhibits excellent adhesion characteristics on the backside of wafers having a finish at least as fine as a 300 grit equivalency while the silver layer exhibits excellent solderability characteristics.
Inventors
- 👤 Ravinder K. Sharma
- 👤 William H. Lytle
- 👤 Angela Rogona
- 👤 Bennett L. Hileman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:31
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W72/00; H10W72/01; H10W72/013; H10W72/01331; H10W72/50; H10W72/59; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12528; Y10T428/12771; Y10T428/12806; Y10T428/12819
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
48 words
A metallization scheme for semiconductor devices comprising: a vanadium layer having a thickness in the range of 500 to 3,000 angstroms disposed on the backside of a wafer; and a silver layer having a thickness in the range of 10,000 to 20,000 angstroms disposed on said vanadium layer.
Claim 2
Dependent Claim
48 words
A metallization scheme for semiconductor devices comprising: a vanadium layer having a thickness in the range of 500 to 3,000 angstroms disposed on the backside of a wafer; and a silver layer having a thickness in the range of 10,000 to 20,000 angstroms disposed on said vanadium layer.
Claim 3
Dependent Claim
38 words
The metallization scheme of claim 1 wherein the vanadium layer is disposed on the backside of a silicon wafer, said backside of said silicon wafer having a backside finish at least as fine as a 300 grit equivalency.
Claim 4
Dependent Claim
31 words
The metallization scheme of claim 1 further comprising an intermediate layer comprising a mixture of vanadium and silver, said intermediate layer being disposed between the vanadium layer and the silver layer.
Claim 5
Dependent Claim
26 words
The metallization scheme of claim 1 further comprising an intermediate layer comprising nickel, said intermediate layer being disposed between the vanadium layer and the silver layer.
Claim 6
Dependent Claim
21 words
The metallization scheme of claim 3 wherein the intermediate layer has a vanadium:silver ratio in the range of 10:90 to 50:50.
Claim 7
Dependent Claim
21 words
The metallization scheme of claim 4 wherein the intermediate layer has a thickness in the range of 500 to 3,000 angstroms.
Claim 8
Dependent Claim
21 words
The metallization scheme of claim 5 wherein the intermediate layer has a thickness in the range of 3,000 to 7,000 angstroms.
Claim 9
Dependent Claim
59 words
A backside metallization scheme for semiconductor devices comprising: a vanadium layer having a thickness in the range of 500 to 3,000 angstroms disposed on the backside of a silicon wafer; an intermediate metal layer disposed on said vanadium layer; and a silver layer having a thickness in the range of 10,000 to 20,000 angstroms disposed on said intermediate layer.
Claim 10
Dependent Claim
59 words
A backside metallization scheme for semiconductor devices comprising: a vanadium layer having a thickness in the range of 500 to 3,000 angstroms disposed on the backside of a silicon wafer; an intermediate metal layer disposed on said vanadium layer; and a silver layer having a thickness in the range of 10,000 to 20,000 angstroms disposed on said intermediate layer.
Claim 11
Dependent Claim
40 words
The metallization scheme of claim 8 wherein the intermediate layer comprises a mixture of vanadium and silver, has a vanadium:silver ratio in the range of 10:90 to 50:50 and has a thickness in the range of 3,000 to 7,000 angstroms.
Claim 12
Dependent Claim
24 words
The metallization scheme of claim 8 wherein the intermediate layer comprises nickel and has a thickness in the range of 500 to 3,000 angstroms.
Claim 13
Dependent Claim
25 words
The metallization scheme of claim 8 wherein the backside of the silicon wafer has a finish at least as fine as a 300 grit equivalency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-06 | 1994-02-05 | 1994-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-06 | 1998-02-05 | 1998-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-06 | 2002-02-05 | 2002-08-07 | $7700.00 | Window Closed / Lapsed |