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US5674774A
Expired / Lapsed
US
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Method of making self-aligned remote polysilicon contacts
Assignee: Bell Semiconductor LLC
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Filing: 1995-06-07
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Granted: 1997-10-07
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Expires: 2015-06-07
Abstract
Abstract Remote electrical contacts for a semiconductor are produced by depositing a polysilicon layer over the entire surface of a semiconductor device and removing a portion of the polysilicon layer by chemi-mechanical polishing. The resulting structure is thereby provided with electrically isolated areas of polysilicon which constitute remote electrical contacts for the semiconductor device. The polysilicon layer or the isolated areas of polysilicon can be salicided to provide very low resistivity. Either the polysilicon layer or the salicide layer can be subjected to ion implantation to provide LDD regions.
Inventors
- 👤 Nicholas F. Pasch
- 👤 Ashok Kapoor
- 👤 Richard D. Schinella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:09
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D64/00; H10D64/20; H10D64/23; H10D64/251; H10D64/258; H10D64/259; H10P30/21; H10P30/212; H10D30/0212; H10D64/01; H10D64/017
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
123 words
A method for providing shallow contacts for a semiconductor device comprising the steps of: providing a semiconductor device comprising a semiconductor substrate, a gate, a source and drain regions, said gate being separated from said source and drain regions by means of insulating material; depositing a polysilicon layer upon all of said gate, source and drain regions, insulating material, and exposed areas of said substrate; chemi-mechanically polishing the resulting polysilicon layer to remove a portion of the polysilicon layer, a portion of said gate, and a portion of said insulating material; and said semiconductor device additionally comprising LDD regions in contact with said source and drain regions and in contact with said gate, said source and drain regions being isolated from said gate.
Claim 2
Independent Claim
123 words
A method for providing shallow contacts for a semiconductor device comprising the steps of: providing a semiconductor device comprising a semiconductor substrate, a gate, a source and drain regions, said gate being separated from said source and drain regions by means of insulating material; depositing a polysilicon layer upon all of said gate, source and drain regions, insulating material, and exposed areas of said substrate; chemi-mechanically polishing the resulting polysilicon layer to remove a portion of the polysilicon layer, a portion of said gate, and a portion of said insulating material; and said semiconductor device additionally comprising LDD regions in contact with said source and drain regions and in contact with said gate, said source and drain regions being isolated from said gate.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said insulating material comprises silicon dioxide.
Claim 4
Dependent Claim
12 words
The method of claim 1, wherein said insulating material comprises silicon nitride.
Claim 5
Dependent Claim
31 words
The method of claim 1, wherein portions of said polysilicon layer remaining after polishing the resulting polysilicon layer to remove a portion of the polysilicon layer are converted to a salicide.
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein said salicide is a refractory metal silicide.
Claim 7
Dependent Claim
26 words
The method of claim 5 wherein said salicide comprises a member selected from the group consisting of tungsten silicide, cobalt silicide, molybdenum silicide, and titanium silicide.
Claim 8
Dependent Claim
20 words
The method of claim 4 wherein said salicide has a resistivity of about 1 to 2.5 ohms per square centimeter.
Claim 9
Dependent Claim
33 words
The method of claim 4 wherein salicide conversion is accomplished by depositing a layer of a refractory metal upon said polysilicon layer and heating to a temperature of at least about 1,000° C.
Claim 10
Dependent Claim
17 words
The method of claim 8 wherein metal remaining after the salicide conversion is removed by chemi-mechanical polishing.
Claim 11
Dependent Claim
35 words
The method of claim 4, wherein the LDD regions in said semiconductor substrate are by ion implanting the LDD regions subsequent to converting the portions of said polysilicon layer remaining after polishing to said salicide.
Claim 12
Dependent Claim
27 words
The method of claim 1, wherein the LDD regions in said semiconductor substrate are by ion implanting the LDD regions subsequent to polishing the resulting polysilicon layer.
Claim 13
Dependent Claim
12 words
The method of claim 1, wherein the semiconductor device is a FET.
Claim 14
Independent Claim
77 words
A method for providing shallow remote contacts on a gated semiconductor comprising: depositing a polysilicon layer upon a gated semiconductor comprising a gate and insulating spacers; chemi-mechanically polishing the resulting polysilicon layer to provide electrically isolated discrete areas of a polysilicon, said areas increasing in thickness towards the gate structure of said gated semiconductor; said chemi-mechanical polishing removing portions of said polysilicon layer, said gate and said insulating spacers; and ion implanting dopant species in said areas.
Claim 15
Independent Claim
77 words
A method for providing shallow remote contacts on a gated semiconductor comprising: depositing a polysilicon layer upon a gated semiconductor comprising a gate and insulating spacers; chemi-mechanically polishing the resulting polysilicon layer to provide electrically isolated discrete areas of a polysilicon, said areas increasing in thickness towards the gate structure of said gated semiconductor; said chemi-mechanical polishing removing portions of said polysilicon layer, said gate and said insulating spacers; and ion implanting dopant species in said areas.
Claim 16
Dependent Claim
14 words
The method of claim 13 which additionally comprises converting said areas into salicide areas.
Claim 17
Dependent Claim
13 words
The method of claim 14 wherein said salicide is a refractory metal silicide.
Claim 18
Dependent Claim
26 words
The method of claim 14 wherein said salicide is a member selected from the group consisting of tungsten silicide, cobalt silicide, molybdenum silicide, and titanium silicide.
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) | 2000-10-06 | 2001-04-07 | 2001-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-06 | 2005-04-07 | 2005-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-06 | 2009-04-07 | 2009-10-07 | $7700.00 | Window Closed / Lapsed |