US4562640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing stable, low resistance contacts in integrated semiconductor circuits
Assignee: Siemens AG
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Filing: 1984-03-22
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Granted: 1986-01-07
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Expires: 2004-03-22
Abstract
Abstract A method of manufacturing stable, low resistance contacts in an integrated semiconductor circuit which involves providing highly doped impurity diffused regions in a silicon substrate, forming a silicon dioxide layer over the highly doped diffused regions and the surrounding substrate, forming contact holes of uniform size in the silicon dioxide layer in selected areas of the highly doped diffused regions, applying a layer including a metal silicide into the holes in contact with the underlying highly doped diffused regions, applying an n + -doped polysilicon layer into the contact holes and over the silicon dioxide layer with a thickness corresponding to about half the contact hole side length, and then depositing a layer of predominantly aluminum over the n + -doped polysilicon layer.
Inventors
- 👤 Dietrich Widmann
- 👤 Reiner Sigusch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:59
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0113; H10W20/40; H10W20/41; H10W20/44; H10W20/4451; Y; Y10; Y10S; Y10S148/00; Y10S148/019
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
168 words
A method of manufacturing stable, low resistance contacts in an integrated semiconductor circuit which comprises: providing highly doped diffused regions in a silicon substrate, forming a silicon dioxide layer over said highly doped diffused regions in the surrounding substrate, forming contact holes of uniform size in said silicon dioxide layer in selected areas of said highly doped diffused regions, said contact holes being matched to the minimum dimensions of the circuit elements, with a plurality of such uniform contact holes being provided in diffused regions of larger area, applying a layer including a metal silicide into said holes in contact with the underlying highly doped diffused region but insufficient to completely fill the contact holes, applying an n + -doped polysilicon layer into the contact holes and over the silicon dioxide layer, the thickness of said n + -doped layer above the contact holes being approximately one-half the length of a side of said contact holes, and depositing a layer of predominantly aluminum over the doped polysilicon layer.
Claim 2
Independent Claim
168 words
A method of manufacturing stable, low resistance contacts in an integrated semiconductor circuit which comprises: providing highly doped diffused regions in a silicon substrate, forming a silicon dioxide layer over said highly doped diffused regions in the surrounding substrate, forming contact holes of uniform size in said silicon dioxide layer in selected areas of said highly doped diffused regions, said contact holes being matched to the minimum dimensions of the circuit elements, with a plurality of such uniform contact holes being provided in diffused regions of larger area, applying a layer including a metal silicide into said holes in contact with the underlying highly doped diffused region but insufficient to completely fill the contact holes, applying an n + -doped polysilicon layer into the contact holes and over the silicon dioxide layer, the thickness of said n + -doped layer above the contact holes being approximately one-half the length of a side of said contact holes, and depositing a layer of predominantly aluminum over the doped polysilicon layer.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein said metal silicide is platinum silicide.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein said aluminum layer contains from 1 to 2% silicon.
Claim 5
Dependent Claim
22 words
A method according to claim 3 wherein copper in an amount of up to 6% is also present in said aluminum layer.
Claim 6
Dependent Claim
29 words
A method according to claim 1 wherein: said n + -doped polysilicon layer is deposited at substantially the same rate on horizontal and vertical portions of the substrate surface.
Claim 7
Dependent Claim
23 words
A method according to claim 5 wherein: said n + -doped polysilicon is deposited by means of a low pressure vapor phase deposition.
Claim 8
Dependent Claim
23 words
A method according to claim 5 wherein: said n + -doped polysilicon is deposited by means of a plasma induced vapor phase deposition.
Claim 9
Dependent Claim
23 words
A method according to claim 5 wherein: said n + -doped polysilicon is deposited by means of a photochemically induced vapor phase deposition.
Claim 10
Dependent Claim
25 words
A method according to claim 1 wherein the n + -doped polysilicon layer is back-etched so that only the contact holes remain filled with polysilicon.
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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) | 1989-01-06 | 1989-07-08 | 1990-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-06 | 1993-07-08 | 1994-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-06 | 1997-07-08 | 1998-01-07 | $7700.00 | Window Closed / Lapsed |