US5028565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for CVD deposition of tungsten layer on semiconductor wafer
Assignee: Applied Materials Inc
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Filing: 1989-08-25
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Granted: 1991-07-02
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Expires: 2009-08-25
Abstract
Abstract An improved process is disclosed for the deposition of a layer of tungsten on a semiconductor wafer in a vacuum chamber wherein the improvements comprise depositing tungsten on the semiconductor wafer in the presence of nitrogen gas to improve the reflectivity of the surface of the resulting layer of tungsten; maintaining the vacuum chamber at a pressure of from about 20 to 760 Torr to improve the deposition rate of the tungsten, as well as to improve the reflectivity of the tungsten surface; and, when needed, the additional step of forming a nucleation layer on the semiconductor layer prior to the step of depositing tungsten on the semiconductor wafer to improve the uniformity of the deposited tungsten layer.
Inventors
- 👤 Mei Chang
- 👤 Cissy Leung
- 👤 David N. Wang
- 👤 David Cheng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:43
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/40; H10W; H10W20/00; H10W20/01; H10W20/031; H10P14/412; H10P14/42; H10P14/43; Y; Y10; Y10S; Y10S148/00; Y10S148/025
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
146 words
An improved process for the deposition of a layer of tungsten on a semiconductor wafer in a vacuum chamber wherein the improvement comprises depositing tungsten on a intermediate layer formed over a silicon dioxide layer on said semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (a) from about 20 to about 200 sccm WF 6 ; (b) from about 100 to about 5000 sccm Ar; (c) from about 10 to about 300 sccm N 2 , and (d) from about 50 to about 2000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 20 to about 760 Torr and the susceptor temperature at from about 450° C. to about 475° C. during said tungsten deposition step wherein the presence of nitrogen gas improves the reflectivity of the resulting layer of tungsten.
Claim 2
Dependent Claim
146 words
An improved process for the deposition of a layer of tungsten on a semiconductor wafer in a vacuum chamber wherein the improvement comprises depositing tungsten on a intermediate layer formed over a silicon dioxide layer on said semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (a) from about 20 to about 200 sccm WF 6 ; (b) from about 100 to about 5000 sccm Ar; (c) from about 10 to about 300 sccm N 2 , and (d) from about 50 to about 2000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 20 to about 760 Torr and the susceptor temperature at from about 450° C. to about 475° C. during said tungsten deposition step wherein the presence of nitrogen gas improves the reflectivity of the resulting layer of tungsten.
Claim 3
Dependent Claim
47 words
The improved process of claim 1 wherein the improvement further comprises the additional step of forming a nucleation layer on the semiconductor wafer over a previously formed titanium nitride intermediate layer and prior to said tungsten deposition step to improve the uniformity of the deposited tungsten layer.
Claim 4
Dependent Claim
42 words
The improved process of claim 1 wherein the improvement further comprises depositing said tungsten at a pressure of from about 60 to 100 Torr to improve the tungsten deposition rate, as well as the reflectivity of the surface of the tungsten layer.
Claim 5
Dependent Claim
155 words
An improved process for the deposition of a layer of tungsten over a layer of silicon dioxide previously formed on a semiconductor wafer in a vacuum chamber wherein the improvement comprises: (a) forming an intermediate layer selected from the group consisting of a tungsten, a titanium tungsten, and a titanium nitride layer over said silicon dioxide layer; and (b) depositing tungsten over said intermediate layer on said semiconductor wafer in the presence of a mixture of gases comprising: (i) from about 20 to about 200 sccm WF 6 ; (ii) from about 100 to about 5000 sccm Ar; (iii) from about 10 to about 300 sccm N 2 , and (iv) from about 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 20 to about 760 Torr and the susceptor temperature at from about 350° C. to about 525° C. during said tungsten deposition step.
Claim 6
Dependent Claim
155 words
An improved process for the deposition of a layer of tungsten over a layer of silicon dioxide previously formed on a semiconductor wafer in a vacuum chamber wherein the improvement comprises: (a) forming an intermediate layer selected from the group consisting of a tungsten, a titanium tungsten, and a titanium nitride layer over said silicon dioxide layer; and (b) depositing tungsten over said intermediate layer on said semiconductor wafer in the presence of a mixture of gases comprising: (i) from about 20 to about 200 sccm WF 6 ; (ii) from about 100 to about 5000 sccm Ar; (iii) from about 10 to about 300 sccm N 2 , and (iv) from about 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 20 to about 760 Torr and the susceptor temperature at from about 350° C. to about 525° C. during said tungsten deposition step.
Claim 7
Dependent Claim
27 words
The improved process of claim 4 wherein the pressure in said vacuum chamber during said deposition is maintained at from about 60 Torr to about 100 Torr.
Claim 8
Dependent Claim
27 words
The improved process of claim 4 wherein the pressure in said vacuum chamber during said deposition is maintained at from about 75 Torr to about 85 Torr.
Claim 9
Dependent Claim
135 words
An improved process for the deposition of a layer of tungsten on an intermediate layer formed over a silicon dioxide layer on a semiconductor wafer in a vacuum chamber wherein the improvement comprises depositing tungsten on said intermediate layer on said semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (a) from about 20 to about 200 sccm WF 6 ; (b) from about 100 to about 5000 sccm Ar; (c) from about 10 to about 300 sccm N 2 , and (d) from about 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 20 Torr to about 760 Torr and the susceptor temperature at from about 350° C. to about 525° during said tungsten deposition step.
Claim 10
Dependent Claim
135 words
An improved process for the deposition of a layer of tungsten on an intermediate layer formed over a silicon dioxide layer on a semiconductor wafer in a vacuum chamber wherein the improvement comprises depositing tungsten on said intermediate layer on said semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (a) from about 20 to about 200 sccm WF 6 ; (b) from about 100 to about 5000 sccm Ar; (c) from about 10 to about 300 sccm N 2 , and (d) from about 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 20 Torr to about 760 Torr and the susceptor temperature at from about 350° C. to about 525° during said tungsten deposition step.
Claim 11
Dependent Claim
35 words
The process of claim 1 which further comprises the additional step of forming a nucleation layer over said intermediate layer prior to said tungsten deposition step to improve the uniformity of the deposited tungsten layer.
Claim 12
Dependent Claim
47 words
The process of claim 8 wherein said step of forming said nucleation layer further comprises contacting said wafer with a mixture of WF 6 , N 2 , Ar, and SiH 4 gases in a vacuum chamber to improve the uniformity of the deposited layer of tungsten.
Claim 13
Dependent Claim
67 words
The improved process of claim 9 wherein the flow rates of said gases flowing through said vacuum chamber to form said nucleation layer comprise: (a) from about 5 to about 50 sccm WF 6 ; (b) from about 500 to about 3000 sccm Ar; (c) from about 20 to about 300 sccm N 2 , and (d) from about 5 to about 50 sccm SiH 4 .
Claim 14
Dependent Claim
46 words
The improved process of claim 7 wherein the improvement further comprises depositing tungsten on a semiconductor wafer at a pressure of from about 60 to about 100 Torr to improve the tungsten deposition rate, as well as the reflectivity of the surface of the tungsten layer.
Claim 15
Dependent Claim
24 words
The improved process of claim 1 wherein the improvement further comprises depositing said tungsten at a pressure of from about 75 to 85 Torr.
Claim 16
Dependent Claim
26 words
The improved process of claim 7 wherein the susceptor temperature is maintained at from about 450° C. to about 475° C. during said tungsten deposition step.
Claim 17
Dependent Claim
136 words
An improved process for the deposition of a layer of tungsten on an intermediate layer formed over a silicon dioxide layer on a semiconductor wafer in a vacuum chamber wherein the improvement comprises depositing tungsten on said intermediate layer on said semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (a) from about 20 to about 200 sccm WF 6 ; (b) from about 100 to about 5000 sccm Ar; (c) from about 10 to about 300 sccm N 2 , and (d) from about 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 75 Torr to about 85 Torr and the susceptor temperature at from about 450° C. to about 475° C. during said tungsten deposition step.
Claim 18
Dependent Claim
136 words
An improved process for the deposition of a layer of tungsten on an intermediate layer formed over a silicon dioxide layer on a semiconductor wafer in a vacuum chamber wherein the improvement comprises depositing tungsten on said intermediate layer on said semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (a) from about 20 to about 200 sccm WF 6 ; (b) from about 100 to about 5000 sccm Ar; (c) from about 10 to about 300 sccm N 2 , and (d) from about 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 75 Torr to about 85 Torr and the susceptor temperature at from about 450° C. to about 475° C. during said tungsten deposition step.
Claim 19
Dependent Claim
42 words
The improved process of claim 14 wherein said intermediate layer comprises titanium nitride and the improvement further comprises the additional step of forming a nucleation layer over said titanium nitride intermediate layer on said semiconductor wafer prior to said tungsten deposition step.
Claim 20
Dependent Claim
47 words
The process of claim 15 wherein said step of forming said nucleation layer further comprises contacting said wafer with a mixture of WF 6 , N 2 , Ar, and SiH 4 gases in a vacuum chamber to improve the uniformity of the deposited layer of tungsten.
Claim 21
Dependent Claim
38 words
The improved process of claim 14 wherein said previously formed intermediate layer over said silicon dioxide layer on said semiconductor wafer is selected from the group consisting of a tungsten, a titanium tungsten, and a titanium nitride layer.
Claim 22
Dependent Claim
212 words
An improved process for the deposition of a layer of tungsten on a semiconductor wafer in a vacuum chamber wherein the improvement comprises: (a) forming a nucleation layer on a semiconductor wafer prior to the step of depositing tungsten on the semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber to form said nucleation layer comprising: (i) from about 5 to about 50 sccm WF 6 ; (ii) from about 500 to about 3000 sccm Ar; (iii) from about 20 to about 300 sccm N 2 , and (iv) from about 5 to about 50 sccm SiH 4 ; and (b) then depositing tungsten on said semiconductor wafer over said nucleation layer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (i) from about 20 to about 200 sccm WF 6 ; (ii) from about 100 to about 5000 sccm Ar; (iii) from about 10 to about 300 sccm N 2 , and (iv) from bout 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 75 Torr to about 85 Torr and the susceptor temperature at from about 450° C. to about 475° C. during said tungsten deposition step.
Claim 23
Dependent Claim
212 words
An improved process for the deposition of a layer of tungsten on a semiconductor wafer in a vacuum chamber wherein the improvement comprises: (a) forming a nucleation layer on a semiconductor wafer prior to the step of depositing tungsten on the semiconductor wafer by contacting said wafer with a mixture of gases flowing through said vacuum chamber to form said nucleation layer comprising: (i) from about 5 to about 50 sccm WF 6 ; (ii) from about 500 to about 3000 sccm Ar; (iii) from about 20 to about 300 sccm N 2 , and (iv) from about 5 to about 50 sccm SiH 4 ; and (b) then depositing tungsten on said semiconductor wafer over said nucleation layer by contacting said wafer with a mixture of gases flowing through said vacuum chamber comprising: (i) from about 20 to about 200 sccm WF 6 ; (ii) from about 100 to about 5000 sccm Ar; (iii) from about 10 to about 300 sccm N 2 , and (iv) from bout 300 to about 3000 sccm H 2 ; while maintaining the pressure in said vacuum chamber at from about 75 Torr to about 85 Torr and the susceptor temperature at from about 450° C. to about 475° C. during said tungsten deposition step.
References Cited (Backward Citations)
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