US4836887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chlorofluorocarbon additives for enhancing etch rates in fluorinated halocarbon/oxidant plasmas
Assignee: International Business Machines Corp
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Filing: 1987-11-23
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Granted: 1989-06-06
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Expires: 2007-11-23
Abstract
Abstract A plasma comprised of a fluorinated gas, an oxidant, and up to 15%-20% chlorofluorocarbon gas etches non-insulating materials such as tungsten and silicon at very high etch rates while providing enhanced etch rate ratios to photoresist and insulators.
Inventors
- 👤 Timothy H. Daubenspeck
- 👤 Faith S. Ichishita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:43
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/24; H10P50/242
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
95 words
A process for etching a refractory metal layer at a rate faster than that of either a polymer layer or an insulator layer, comprising the step of exposing the layers to a gaseous plasma comprising an oxidant gas, a fluorine-based halocarbon gas selected from the group consisting of CF 4 and CHF 3 , and up to approximately 20% of chlorofluorocarbon gas, said chlorofluorocarbon gas being present in an amount sufficient to enhance the refractory metal etch rate, and said fluorine-based halocarbon gas being present in an amount greater than that of said chlorofluorocarbon gas.
Claim 2
Dependent Claim
95 words
A process for etching a refractory metal layer at a rate faster than that of either a polymer layer or an insulator layer, comprising the step of exposing the layers to a gaseous plasma comprising an oxidant gas, a fluorine-based halocarbon gas selected from the group consisting of CF 4 and CHF 3 , and up to approximately 20% of chlorofluorocarbon gas, said chlorofluorocarbon gas being present in an amount sufficient to enhance the refractory metal etch rate, and said fluorine-based halocarbon gas being present in an amount greater than that of said chlorofluorocarbon gas.
Claim 3
Dependent Claim
43 words
In a process for etching tungsten, in a CF 4 /O 2 plasma, the addition of approximately 5%-20% chlorofluorocarbon gas to said plasma to enhance the tungsten etch rate, wherein the amount of CF 4 is greater than that of said chlorofluorocarbon gas.
Claim 4
Dependent Claim
43 words
In a process for etching tungsten, in a CF 4 /O 2 plasma, the addition of approximately 5%-20% chlorofluorocarbon gas to said plasma to enhance the tungsten etch rate, wherein the amount of CF 4 is greater than that of said chlorofluorocarbon gas.
Claim 5
Dependent Claim
25 words
The method as recited in claim 2, wherein said chlorofluorocarbon is selected from the group consisting of CCl 2 F 2 and CF 3 Cl.
Claim 6
Dependent Claim
29 words
The method as recited in claim 3, wherein said plasma is generated in a chamber having a pressure of approximately 55 mTorr and a power of 300 l W.
Claim 7
Dependent Claim
43 words
In a process for etching tungsten, in a CHF 3 /O 2 plasma, the addition of approxmately 1%-10% chlorofluorocarbon gas to said plasma to enhance the tungsten etch rate, wherein the amount of CHF 3 is greater than that of said chlorofluorocarbon gas.
Claim 8
Dependent Claim
43 words
In a process for etching tungsten, in a CHF 3 /O 2 plasma, the addition of approxmately 1%-10% chlorofluorocarbon gas to said plasma to enhance the tungsten etch rate, wherein the amount of CHF 3 is greater than that of said chlorofluorocarbon gas.
Claim 9
Dependent Claim
25 words
The method as recited in claim 5, wherein said chlorofluorocarbon is selected from the group consisting of CCl 2 F 2 and CF 3 Cl.
Claim 10
Dependent Claim
28 words
The method as recited in claim 6, wherein said plasma is generated in a chamber having a pressure of approximately 55 mTorr and a power of 300 W.
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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) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |