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US5654242A
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Method for making refractory metal silicide electrode
Assignee: Sony Corp
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Filing: 1995-09-25
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Granted: 1997-08-05
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Expires: 2015-09-25
Abstract
Abstract A WSi x layer wherein the value of x as the stoichiometry of Si is not less than 2.7 and preferably not less than 3.0 is formed by LPCVD based upon reduction of SiCl 2 H 2 of WF 6 . Even if this WSi x film is used without an adhesion layer such as poly Si (polycide structure), it is excellent in adhesion with respect to an SiO 2 film and provides a gate electrode capable of maintaining a satisfactory breakdown voltage value of a gate oxide film. If n-type and p-type impurities are ion-implanted into an nMOS forming region and a pMOS forming region of the WSi x layer and patterned, a gate electrode of a reduced thickness and a low resistance having a controlled work function may be formed for providing symmetrical threshold voltages.
Inventors
- 👤 Hiroshi Komatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:38
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01318; H10D64/0132; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/0172; H10D84/0174; H10D84/0177; H10D84/02; H10D84/03; H10D84/038
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
A method for producing an electrode comprising the steps of: forming a refractory metal silicide film on a substrate by carrying out chemical vapor deposition using a gas mixture containing a refractory metal fluoride and a chlorosilane based compound; introducing impurity for controlling the work function into said refractory metal silicide film, said impurity being introduced so that the range of impurity concentration of said refractory metal silicide film is from about 10 20 to 10 22 /cm 3 ; heat treating the impurity in the refractory silicide film in an atmosphere containing not less than 10% by volume of O 2 or N 2 ; and patterning said refractory metal silicide film for forming a metallization layer.
Claim 2
Independent Claim
118 words
A method for producing an electrode comprising the steps of: forming a refractory metal silicide film on a substrate by carrying out chemical vapor deposition using a gas mixture containing a refractory metal fluoride and a chlorosilane based compound; introducing impurity for controlling the work function into said refractory metal silicide film, said impurity being introduced so that the range of impurity concentration of said refractory metal silicide film is from about 10 20 to 10 22 /cm 3 ; heat treating the impurity in the refractory silicide film in an atmosphere containing not less than 10% by volume of O 2 or N 2 ; and patterning said refractory metal silicide film for forming a metallization layer.
Claim 3
Dependent Claim
42 words
The method as claimed in claim 1, wherein in the step of forming said refractory metal silicide film, a tungsten silicide film represented by the formula WSi x , where x≧2.7, is formed using a gas mixture containing tungsten hexafluoride and dichlorosilane.
Claim 4
Dependent Claim
19 words
The method as claimed in claim 1, wherein the heat treatment is carried out after patterning said metallization layer.
Claim 5
Independent Claim
138 words
A method for producing an electrode comprising the steps of: forming a refractory metal silicide film on a substrate by carrying out chemical vapor deposition using a gas mixture containing a refractory metal fluoride and a chlorosilane based compound; introducing impurity for controlling the work function into said refractory metal silicide film, said impurity being introduced so that the range of impurity concentration of said refractory metal silicide film is from about 10 20 to 10 22 /cm 3 ; heat treating the impurity in the refractory silicide film in an atmosphere containing not less than 10% by volume of O 2 or N 2 ; forming a barrier film for preventing diffusion of the impurity in said refractory metal silicide; and collectively patterning said barrier film and said refractory metal silicide film for forming a metallization layer.
Claim 6
Independent Claim
138 words
A method for producing an electrode comprising the steps of: forming a refractory metal silicide film on a substrate by carrying out chemical vapor deposition using a gas mixture containing a refractory metal fluoride and a chlorosilane based compound; introducing impurity for controlling the work function into said refractory metal silicide film, said impurity being introduced so that the range of impurity concentration of said refractory metal silicide film is from about 10 20 to 10 22 /cm 3 ; heat treating the impurity in the refractory silicide film in an atmosphere containing not less than 10% by volume of O 2 or N 2 ; forming a barrier film for preventing diffusion of the impurity in said refractory metal silicide; and collectively patterning said barrier film and said refractory metal silicide film for forming a metallization layer.
Claim 7
Dependent Claim
42 words
The method as claimed in claim 4, wherein in the step of forming said refractory metal silicide film, a tungsten silicide film represented by the formula WSi x , where x≧2.7, is formed using a gas mixture containing tungsten hexafluoride and dichlorosilane.
Claim 8
Dependent Claim
19 words
The method as claimed in claim 4, wherein the heat treatment is carried out after patterning said metallization layer.
Claim 9
Dependent Claim
18 words
The method as claimed in claim 4, wherein said electrode is a gate electrode of a MOS transistor.
Claim 10
Dependent Claim
24 words
A method as defined in claim 1, wherein in said heat-treating step the substrate is heated to about 850° C. for about 30 minutes.
Claim 11
Dependent Claim
24 words
A method as defined in claim 4, wherein in said heat-treating step the substrate is heated to about 850° C. for about 30 minutes.
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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) | 2000-08-04 | 2001-02-03 | 2001-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-04 | 2005-02-03 | 2005-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-04 | 2009-02-03 | 2009-08-05 | $7700.00 | Window Closed / Lapsed |