EP0785574A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of forming tungsten-silicide
Assignee: Applied Materials Inc
•
Filing: 1997-01-08
•
Granted: —
•
Expires: 2017-01-08
Abstract
Abstract A method of forming a silicide on a silicon layer. First, a monosilane based tungsten-silicide layer is formed on the silicon layer. Next, a dichlorosilane based tungsten-silicide layer is formed on the monosilane based tungsten-silicide layer.
Inventors
- 👤 Cory M. Czarnik
- 👤 Klaus-Dieter Rinnen
- 👤 Vedapuram S. Achutharaman
- 👤 Mahalingam Venkatesan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 14:30
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/42; H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/066; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01308; H10D64/01312
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
66 words
A method of forming a silicide on a silicon layer comprising the steps of: forming a first tungsten-silicide layer on said silicon layer wherein said first tungsten-silicide layer is formed from a first gas mix comprising monosilane (SiH 4 ); and forming a second tungsten-silicide layer on said first tungsten-silicide layer wherein said second tungsten-silicide layer is formed from a second gas mix comprising dichlorosilane (DCS).
Claim 2
Dependent Claim
32 words
A method as claimed in claim 1 further comprising the step of: exposing said silicon layer to a third gas comprising monosilane (SiH 4 ) prior to forming said first tungsten-silicide layer.
Claim 3
Dependent Claim
26 words
A method as claimed in claim 1 or claim 2 further comprising the step of exposing said second tungsten-silicide layer to a fourth gas comprising silane.
Claim 4
Independent Claim
35 words
A method as claimed in any one of the preceding claims, wherein said first gas mix further comprises WF 6 and said first gas mix has a WF 6 :SiH 4 ratio of approximately 1:100.
Claim 5
Independent Claim
30 words
A method as claimed in any one of the preceding claims wherein said first tungsten-silicide layer is formed at a pressure between 0.2-10 T and at a temperature between 450-625°C.
Claim 6
Independent Claim
18 words
A method as claimed in any one of the preceding claims wherein said silicon layer is polycrystalline silicon.
Claim 7
Independent Claim
18 words
A method as claimed in any one of the preceding claims wherein said silicon layer is amorphous silicon.
Claim 8
Independent Claim
95 words
A method of forming a silicide on a doped polysilicon layer comprising the steps of: exposing said doped polysilicon layer to a first gas mix comprising monosilane (SiH 4 ) to form a monosilane exposed polysilicon surface; forming a first tungsten-silicide layer on said monosilane exposed doped polysilicon surface wherein said first tungsten-silicide layer is formed from a reduction reaction of SiH 4 and WF 6 ; and forming a second tungsten-silicide layer on said first tungsten-silicide layer wherein said second tungsten-silicide layer is formed from a reduction reaction of DCS and WF 6 .
Claim 9
Dependent Claim
20 words
A method as claimed in claim 8 wherein said first tungsten-silicide layer is formed to a thickness of approximately 100Å.
Claim 10
Dependent Claim
31 words
A method as claimed in claim 8 or claim 9 wherein said first tungsten-silicide layer is formed from a gas mix having a WF 6 :SiH 4 ratio of approximately 1:100.
Claim 11
Independent Claim
33 words
A method as claimed in any one of the preceding claims wherein said first tungsten-silicide layer has a Si:W ratio greater than or equal to the Si:W ratio in said second tungsten-silicide layer.
Claim 12
Independent Claim
29 words
A method as claimed in any one of claims 8 to 11 further comprising the step of exposing said second tungsten-silicide layer to a second gas mix comprising silane.
Claim 13
Dependent Claim
36 words
A composite thin film comprising: a silicon layer; A SiH 4 based tungsten-silicide layer formed on said silicon layer; and a SiH 2 Cl 2 based tungsten-silicide layer formed on said SiH 4 based tungsten-silicide layer.
Claim 14
Dependent Claim
22 words
A composite thin film as claimed in claim 13 wherein said SiH 4 based tungsten-silicide layer has a thickness of approximately 100Å.
Claim 15
Dependent Claim
41 words
A composite thin film as claimed in claim 13 or claim 14 wherein the Si:W ratio of said SiH 4 based tungsten-silicide layer is greater than or equal to the Si:W ratio of said SiH 2 Cl 2 based tungsten-silicide layer.
Claim 16
Dependent Claim
23 words
A composite thin film as claimed in any one of claims 13 to 15 wherein said silicon layer is an amorphous silicon layer.
Claim 17
Dependent Claim
23 words
A composite thin film as claimed in any one of claims 13 to 16 wherein said silicon layer is a polycrystalline silicon layer.
Claim 18
Dependent Claim
21 words
A composite thin film as claimed in any one of claims 13 to 17 wherein said polycrystalline silicon layer is doped.
Claim 19
Dependent Claim
32 words
A composite thin film as claimed in any one of claims 13 to 18 wherein said monosilane based tungsten-silicide layer is substantially thicker than said SiH 2 Cl 2 based tungsten-silicide layer.
Claim 20
Independent Claim
28 words
A method of forming a thin film comprising the steps of: forming an amorphous silicon layer; and forming a dichlorosilane based tungsten-silicide layer on said amorphous silicon layer.
Claim 21
Dependent Claim
23 words
A method as claimed in claim 20 further comprising the step of annealing said thin film to convert said amorphous silicon to polysilicon.
Claim 22
Dependent Claim
17 words
A method as claimed in claim 20 or claim 21 wherein said amorphous silicon layer is doped.
Claim 23
Independent Claim
32 words
A method as claimed in any one of claims 20 to 22 wherein said dichlorosilane based tungsten-silicide layer is formed from a reaction of WF 6 and SiH 2 Cl 2 .
Claim 24
Dependent Claim
19 words
A thin film comprising: an amorphous silicon layer; and a dichlorosilane based tungsten-silicide layer on said amorphous silicon layer.
Claim 25
Dependent Claim
15 words
A thin film as claimed in claim 24 wherein said amorphous silicon layer is doped.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.