US4918033A
Expired / Lapsed
US
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PECVD (plasma enhanced chemical vapor deposition) method for depositing of tungsten or layers containing tungsten by in situ formation of tungsten fluorides
Assignee: International Business Machines Corp
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Filing: 1988-09-01
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Granted: 1990-04-17
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Expires: 2008-09-01
Abstract
Abstract The invention comprises a PECVD method for the deposition of refractory metal layers or layers containing refractory metal by the in situ formation of refractory metal fluorides. For this purpose, an etch gas, such as CF 4 , NF 3 , SF 6 etc., is introduced into a plasma deposition chamber which comprises a cathode, with a refractory metal sheet electrically connected thereto, and an anode carrying wafers. In a preferred example, CF 6 is introduced into the chamber and, via a gas shower, into a cathode region. After ignition of a plasma, the ionized etch gas acts on a tungsten sheet, generating WF x ions that diffuse towards a target with wafers. The WF x ions thus produced are suitable for the deposition of a tungsten layer or a layer containing tungsten on silicon wafers.
Inventors
- 👤 Johann W. Bartha
- 👤 Thomas Bayer
- 👤 Johann Greschner
- 👤 Georg Kraus
- 👤 Gerhard Schmid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:47
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/448; C23C16/4488; C23C16/06; C23C16/08; H; H10; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; Y; Y10; Y10S; Y10S148/00; Y10S148/147
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
154 words
A PECVD method for depositing a refractory metal layer on a semiconductor substrate in a plasma deposition chamber, which comprises a refractory metal cathode and an anode, comprising reacting a fluoro compound etch gas with the refractory metal cathode in said deposition chamber to convert said metal to gaseous refractory metal fluorides, wherein said cathode comprises a refractory metal sheet and an electrode and the gaseous refractory metal fluorides are generated by etching said sheet, and wherein the electrode and the refractory metal sheet are electrically connected to form a hollow cathode region, a higher concentration of refractory metal fluoride radicals being generated in the region between said electrode and said refractory metal sheet owing to a higher ionization level of discharge in said region, and depositing a layer of said refractory metal on a semiconductor substrate positioned on the anode of said chamber by exposing said substrate to said gaseous refractory metal fluorides.
Claim 2
Dependent Claim
154 words
A PECVD method for depositing a refractory metal layer on a semiconductor substrate in a plasma deposition chamber, which comprises a refractory metal cathode and an anode, comprising reacting a fluoro compound etch gas with the refractory metal cathode in said deposition chamber to convert said metal to gaseous refractory metal fluorides, wherein said cathode comprises a refractory metal sheet and an electrode and the gaseous refractory metal fluorides are generated by etching said sheet, and wherein the electrode and the refractory metal sheet are electrically connected to form a hollow cathode region, a higher concentration of refractory metal fluoride radicals being generated in the region between said electrode and said refractory metal sheet owing to a higher ionization level of discharge in said region, and depositing a layer of said refractory metal on a semiconductor substrate positioned on the anode of said chamber by exposing said substrate to said gaseous refractory metal fluorides.
Claim 3
Dependent Claim
38 words
The method of claim 1, wherein said etch gas for etching the refractory metal cathode to form gaseous refractory metal fluorides is selected from the group consisting of CF 4 , NF 3 , and SF 6 .
Claim 4
Dependent Claim
28 words
The method of claim 1, wherein said electrode and said refractory metal sheet are about the same size and are spaced from each other by about 1 cm.
Claim 5
Dependent Claim
16 words
The method of claim 3, wherein said refractory metal sheet is a tungsten or molybdenum sheet.
Claim 6
Independent Claim
35 words
The method of any of claims 1-3 or 4, wherein said refractory metal sheet is a tungsten sheet, said etch gas is CF 4 , and said gaseous refractory metal fluorides are WF x .
Claim 7
Dependent Claim
16 words
The method of claim 1, wherein said semiconductor substrate is selected from silicon dioxide or silicon.
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) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |