Patent US4867841A successfully refreshed from Google Patents.
US4867841A
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Method for etch of polysilicon film
Assignee: Texas Instruments Inc
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Filing: 1988-05-27
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Granted: 1989-09-19
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Expires: 2008-05-27
Abstract
Abstract A process for etch of polysilicon films which utilizes the combination of remote and in situ plasma in a low pressure process module and the plasma is generated from a mixture of Helium and a source of Fluorine with the process chamber within the process module being generally at ambient temperatures.
Inventors
- 👤 Lee M. Loewenstein
- 👤 Cecil J. Davis
- 👤 Rhett B. Jucha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:31
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
72 words
A process for etch of polysilicon film comprising the steps of: (a) disposing said film in a low pressure process chamber; (b) generating remote plasma from a gas comprises of a mixture of a source of Fluorine and Helium; (c) introducing said remote plasma into said chamber and to said film; and (d) generating an in situ plasma within said chamber from a gas mixture of a source of Fluorine and Helium.
Claim 2
Dependent Claim
72 words
A process for etch of polysilicon film comprising the steps of: (a) disposing said film in a low pressure process chamber; (b) generating remote plasma from a gas comprises of a mixture of a source of Fluorine and Helium; (c) introducing said remote plasma into said chamber and to said film; and (d) generating an in situ plasma within said chamber from a gas mixture of a source of Fluorine and Helium.
Claim 3
Dependent Claim
18 words
The process as set forth in claim 1 wherein said remote and in situ plasmas are generated simultaneously.
Claim 4
Dependent Claim
38 words
The process as set forth in claim 1 wherein wherein said source of Fluorine is one or more of the groups of CF 4 , F 2 , NF 3 , SF 6 , and CHF 3 .
Claim 5
Dependent Claim
17 words
The process as set forth in claim 1 wherein the process is carrier out at ambient temperature.
Claim 6
Dependent Claim
16 words
The process as set forth in claim 1 wherein wherein the low pressure is 0.7 Torr.
Claim 7
Dependent Claim
32 words
The process as set forth in claim 1 wherein mixture for the in situ and remote plasmas has a flow comprised of Helium at 1000 sccm and CF 4 at 200 sccm.
Claim 8
Dependent Claim
34 words
The process as set forth in claim 1 wherein the power utilized for generating the remote plasma is 400 watts at 2450 MHz and the in situ plasma is 225 watts at 13.56 MHz.
Claim 9
Dependent Claim
62 words
A process for etch of polysilicon film in a process chamber, comprising the steps of: (a) generating free radicals from a source of fluorine and helium in a plasma generating chamber remote from the process chamber; (b) introducing the free radicals into said chamber and to said film; and (c) generating an in situ plasma within said chamber from the free radicals.
Claim 10
Dependent Claim
62 words
A process for etch of polysilicon film in a process chamber, comprising the steps of: (a) generating free radicals from a source of fluorine and helium in a plasma generating chamber remote from the process chamber; (b) introducing the free radicals into said chamber and to said film; and (c) generating an in situ plasma within said chamber from the free radicals.
Claim 11
Dependent Claim
19 words
The process as set forth in claim 8 wherein the free radicals and in situ plasmas are generated simultaneously.
Claim 12
Dependent Claim
36 words
The process as set forth in claim 8 wherein the source of fluorine is taken from the group consisting of CF 4 , F 2 , NF 3 , SF 6 , and CHF 3 .
Claim 13
Dependent Claim
17 words
The process as set forth in claim 8 wherein the process is carrier out at ambient temperature.
Claim 14
Dependent Claim
19 words
The process as set forth in claim 8 wherein the face of the wafer to be processed faces downward.
Claim 15
Dependent Claim
17 words
The process as set forth in claim 8 wherein the process is carrier out at 0.7 Torr.
Claim 16
Dependent Claim
32 words
The process as set forth in claim 8 wherein mixture for the in situ and remote plasmas has a flow comprised of Helium at 1000 sccm and CF 4 at 200 sccm.
Claim 17
Dependent Claim
34 words
The process as set forth in claim 8 wherein the power utilized for generating the remote plasma is 400 watts at 2450 MHz and the in situ plasma is 225 watts at 13.56 MHz.
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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) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |