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Patent US4545116A successfully refreshed from Google Patents.
US4545116A
Expired / Lapsed
US
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Method of forming a titanium disilicide
Assignee: Texas Instruments Inc
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Filing: 1983-05-06
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Granted: 1985-10-08
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Expires: 2003-05-06
Abstract
Abstract A method of forming a metallic silicide on silicon or polysilicon in which a masking layer such as silicon dioxide is formed on a silicon slice and patterned to expose selected areas of the slice surface. The slice is then sputter etched followed by in situ deposition of a metal layer. The slice is heated to convert the portion of the metal layer in contact with the silicon and/or polysilicon to a metal silicide, then the non-converted metal is removed by a selective etchant. According to another embodiment of the invention a titanium layer is deposited and reacted in an ambient including nitrogen to prevent the out-diffusion of silicon through the TiSi 2 and titanium layers.
Inventors
- 👤 Chi K. Lau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:36
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10D64/012; H10D64/0121; Y; Y10; Y10S; Y10S148/00; Y10S148/147
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
80 words
A method of forming titanium disilicide comprising the steps of: forming and patterning an insulating layer on a silicon layer to expose selected surface areas thereof; forming a titanium layer overlying said insulating layer and said selected surface areas; and heating the resulting structure to a temperature less than about 700° C. in an atmosphere comprising nitrogen to form titanium disilicide on said selected silicon surface areas in contact with said titanium layer whereby silicon nitride formation is effectively prevented.
Claim 2
Independent Claim
80 words
A method of forming titanium disilicide comprising the steps of: forming and patterning an insulating layer on a silicon layer to expose selected surface areas thereof; forming a titanium layer overlying said insulating layer and said selected surface areas; and heating the resulting structure to a temperature less than about 700° C. in an atmosphere comprising nitrogen to form titanium disilicide on said selected silicon surface areas in contact with said titanium layer whereby silicon nitride formation is effectively prevented.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said insulating layer comprises silicon dioxide.
Claim 4
Dependent Claim
32 words
The method of claim 2 wherein said step of forming said titanium layer is immediately preceded by the step of sputter etching said silicon and silicon dioxide layers in an inert atmosphere.
Claim 5
Dependent Claim
35 words
The method of claim 2 wherein said step of forming and patterning said silicon dioxide layer is followed by the step of forming and patterning a layer of polycrystalline silicon on said silicon dioxide layer.
Claim 6
Dependent Claim
35 words
The method of claim 3 wherein said step of forming and patterning said silicon dioxide layer is followed by the step of forming and patterning a layer of polycrystalline silicon on said silicon dioxide layer.
Claim 7
Independent Claim
62 words
A method of forming titanium disilicide, comprising the steps of: forming a patterned polycrystalline silicon layer on an insulating layer; forming a titanium layer overall; and heating the resulting structure to a temperature less than about 700° C. in an ambient comprising nitrogen to form titanium disilicide in the titanium layer overlying the polycrystalline layer whereby silicon nitride formation is effectively prevented.
Claim 8
Independent Claim
62 words
A method of forming titanium disilicide, comprising the steps of: forming a patterned polycrystalline silicon layer on an insulating layer; forming a titanium layer overall; and heating the resulting structure to a temperature less than about 700° C. in an ambient comprising nitrogen to form titanium disilicide in the titanium layer overlying the polycrystalline layer whereby silicon nitride formation is effectively prevented.
Claim 9
Independent Claim
87 words
A method of forming titanium disilicide, comprising the steps of: patterning an insulating layer on a silicon substrate to form openings therein; forming and patterning a layer of polycrystalline silicon over the insulating layer; forming a layer of titanium overall; heating the resulting structure to a temperature less than about 700° C. in an atmosphere containing nitrogen to form titanium disilicide over the openings and over the polycrystalline silicon whereby silicon nitride formation is effectively prevented; and removing the titanium which has not been converted to disilicide.
Claim 10
Independent Claim
87 words
A method of forming titanium disilicide, comprising the steps of: patterning an insulating layer on a silicon substrate to form openings therein; forming and patterning a layer of polycrystalline silicon over the insulating layer; forming a layer of titanium overall; heating the resulting structure to a temperature less than about 700° C. in an atmosphere containing nitrogen to form titanium disilicide over the openings and over the polycrystalline silicon whereby silicon nitride formation is effectively prevented; and removing the titanium which has not been converted to disilicide.
Claim 11
Independent Claim
67 words
A method of forming titanium disilicide, comprising the steps of: forming a patterned polycrystalline silicon layer on an insulating layer; forming a titanium layer overall; and heating the resulting structure to a temperature less than about 700° C. in an ambient comprising nitrogen to prevent silicon outdiffusion and to form titanium disilicide in the titanium layer overlying the polycrystalline layer whereby silicon nitride formation is effectively prevented.
Claim 12
Independent Claim
67 words
A method of forming titanium disilicide, comprising the steps of: forming a patterned polycrystalline silicon layer on an insulating layer; forming a titanium layer overall; and heating the resulting structure to a temperature less than about 700° C. in an ambient comprising nitrogen to prevent silicon outdiffusion and to form titanium disilicide in the titanium layer overlying the polycrystalline layer whereby silicon nitride formation is effectively prevented.
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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |