Patent US4857140A successfully refreshed from Google Patents.
US4857140A
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Method for etching silicon nitride
Assignee: Texas Instruments Inc
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Filing: 1988-03-31
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Granted: 1989-08-15
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Expires: 2008-03-31
Abstract
Abstract A process for etching silicon nitride which utilizes free radicals from a remote plasma generated using a fluorine containing gas; and hydrogen; to produce an etch which is selective to selected materials, for example, silicon and silicon dioxide.
Inventors
- 👤 Lee M. Loewenstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:17
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
48 words
A process for etch of a silicon nitride film comprising the steps of: (a) generating at least free radicals from a gas containing at least a fluorine source in a plasma generator remote from a process chamber; and (b) introducing said gas mixture and a source of hydrogen.
Claim 2
Dependent Claim
48 words
A process for etch of a silicon nitride film comprising the steps of: (a) generating at least free radicals from a gas containing at least a fluorine source in a plasma generator remote from a process chamber; and (b) introducing said gas mixture and a source of hydrogen.
Claim 3
Dependent Claim
22 words
The process as set forth in claim 1 wherein said source of hydrogen is added to said gas inside said process chamber.
Claim 4
Dependent Claim
25 words
The process as set forth in claim 1 wherein said source of hydrogen is added to said gas before generating said at least free radicals.
Claim 5
Dependent Claim
25 words
The process as set forth in claim 1 wherein said source of hydrogen is added to said gas after generating said at least free radicals.
Claim 6
Dependent Claim
35 words
The process as set forth in claim 1 wherein the fluorine source is taken from the group of CF 4 , F 2 , SF 6 and C 2 F 6 singly or in combination.
Claim 7
Dependent Claim
16 words
The process as set forth in claim 1 wherein the fluorine source is CF 4 .
Claim 8
Dependent Claim
16 words
The process as set forth in claim 1 wherein the fluorine source is SF 6 .
Claim 9
Dependent Claim
36 words
The process as set forth in claim 1 wherein the hydrogen source is taken from the group of CH 4 , H 2 , NH 3 , hydrocarbon or any molecule with an abstractable hydrogen atom.
Claim 10
Dependent Claim
42 words
The process as set forth in claim 1 wherein the Fluorine source is taken from the group of CF 4 , F 2 , SF 6 , C 2 F 6 , NF 3 , and CHF 3 singly or in combination.
Claim 11
Dependent Claim
17 words
The process as set forth in claim 1 wherein the process is carried out at 200° C.
Claim 12
Dependent Claim
38 words
The process as set forth in claim 1 wherein the low pressure is 1 Torr and wherein the mixture has a flow comprised of helium at 2200 sccm, hydrogen at 30 sccm, and CF 4 at 210 sccm.
Claim 13
Dependent Claim
38 words
The process as set forth in claim 1 wherein the low pressure is 0.45 Torr and wherein the mixture has a flow comprised of Helium at 500 sccm, hydrogen at 30 sccm, and CF 4 at 210 sccm.
Claim 14
Dependent Claim
38 words
The process as set forth in claim 1 wherein the low pressure is 0.915 Torr and wherein the mixture has a flow comprised of Helium at 2200 sccm, hydrogen at 68 sccm, and SF 6 at 27.5 sccm.
Claim 15
Dependent Claim
107 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) disposing said film in a low pressure process chamber; (b) generating at least free radicals from a gas comprised of a gas taken from the group of CF 4 , F 2 , SF 6 , CFH 3 , and C 2 F 6 and an inert carrier taken from the group of helium, argon, or nitrogen; and (c) introducing said gas and a source of hydrogen taken from the group of CH 4 , H 2 , NH 3 , hydrocarbon or any molecule with an abstractable hydrogen atom to said film.
Claim 16
Dependent Claim
107 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) disposing said film in a low pressure process chamber; (b) generating at least free radicals from a gas comprised of a gas taken from the group of CF 4 , F 2 , SF 6 , CFH 3 , and C 2 F 6 and an inert carrier taken from the group of helium, argon, or nitrogen; and (c) introducing said gas and a source of hydrogen taken from the group of CH 4 , H 2 , NH 3 , hydrocarbon or any molecule with an abstractable hydrogen atom to said film.
Claim 17
Dependent Claim
22 words
The process as set forth in claim 14 wherein said source of hydrogen is added to said gas inside said process chamber.
Claim 18
Dependent Claim
25 words
The process as set forth in claim 14 wherein said source of hydrogen is added to said gas before generating said at least free radicals.
Claim 19
Dependent Claim
25 words
The process as set forth in claim 14 wherein said source of hydrogen is added to said gas after generating said at least free radicals.
Claim 20
Dependent Claim
17 words
The process as set forth in claim 14 wherein the process is carried out at 200° C.
Claim 21
Dependent Claim
38 words
The process as set forth in claim 14 wherein the low pressure is 1 Torr and wherein the mixture has a flow comprised of Helium at 2200 sccm, hydrogen at 30 sccm, and CF 4 at 210 sccm.
Claim 22
Dependent Claim
38 words
The process as set forth in claim 14 wherein the low pressure is 0.45 Torr and wherein the mixture has a flow comprised of Helium at 500 sccm, hydrogen at 30 sccm, and CF 4 at 210 sccm.
Claim 23
Dependent Claim
38 words
The process as set forth in claim 14 wherein the low pressure is 0.915 Torr and wherein the mixture has a flow comprised of Helium at 2200 sccm, hydrogen at 68 sccm, and SF 6 at 27.5 sccm.
Claim 24
Dependent Claim
46 words
A process for etch of a silicon nitride film comprising the steps of: (a) generating at least free radical from a gas containing SF 6 in a plasma generator remote from a process chamber; and (b) introducing said gas and source of hydrogen to said film.
Claim 25
Dependent Claim
46 words
A process for etch of a silicon nitride film comprising the steps of: (a) generating at least free radical from a gas containing SF 6 in a plasma generator remote from a process chamber; and (b) introducing said gas and source of hydrogen to said film.
Claim 26
Dependent Claim
22 words
The process as set forth in claim 22 wherein said source of hydrogen is added to said gas inside said process chamber.
Claim 27
Dependent Claim
25 words
The process as set forth in claim 22 wherein said source of hydrogen is added to said gas before generating said at least free radicals.
Claim 28
Dependent Claim
25 words
The process as set forth in claim 22 wherein said source of hydrogen is added to said gas after generating said at least free radicals.
Claim 29
Dependent Claim
33 words
The process as set forth in claim 22 wherein at least one taken from the group of CF 4 , F 2 , and C 2 F 6 is added to said gas.
Claim 30
Dependent Claim
39 words
The process as set forth in claim 22 wherein the hydrogen source is taken from the group of CH 4 , H 2 , NH 3 , CHF 3 , hydrocarbon or any molecule with an abstractable hydrogen atom.
Claim 31
Dependent Claim
39 words
The process as set forth in claim 22 wherein at least one taken from the group of CF 4 , F 2 , C 2 F 6 , NF 3 , and CHF 3 is added to said gas.
Claim 32
Dependent Claim
17 words
The process as set forth in claim 22 wherein the process is carried out at 200° C.
Claim 33
Dependent Claim
38 words
The process as set forth in claim 22 wherein the low pressure is 0.915 Torr and wherein the mixture has a flow comprised of Helium at 2200 sccm, hydrogen at 68 sccm, and SF 6 at 27.5 sccm.
Claim 34
Dependent Claim
29 words
The process as set forth in claim 22 further including a cleanup of the process chamber using free radicals generated in a plasma generator remote from the process chamber.
Claim 35
Dependent Claim
76 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) disposing said film in a low pressure process chamber; (b) generating at least free radicals from a gas comprised of SF 6 and an inert carrier in a plasma generator remote from said process chamber; (c) introducing said gas and a source of hydrogen and to said film; and (d) generating an insitu plasma from said gas and said source of hydrogen.
Claim 36
Dependent Claim
76 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) disposing said film in a low pressure process chamber; (b) generating at least free radicals from a gas comprised of SF 6 and an inert carrier in a plasma generator remote from said process chamber; (c) introducing said gas and a source of hydrogen and to said film; and (d) generating an insitu plasma from said gas and said source of hydrogen.
Claim 37
Dependent Claim
22 words
The process as set forth in claim 32 wherein said source of hydrogen is added to said gas inside said process chamber.
Claim 38
Dependent Claim
25 words
The process as set forth in claim 32 wherein said source of hydrogen is added to said gas before generating said at least free radicals.
Claim 39
Dependent Claim
25 words
The process as set forth in claim 32 wherein said source of hydrogen is added to said gas after generating said at least free radicals.
Claim 40
Dependent Claim
33 words
The process as set forth in claim 32 wherein at least one take from the group of CF 4 , F 2 , and C 2 F 6 is added to said gas.
Claim 41
Dependent Claim
36 words
The process as set forth in claim 32 wherein the hydrogen source is taken from the group of CH 4 , H 2 , NH 3 , hydrogen or any molecule with an abstractable hydrogen atom.
Claim 42
Dependent Claim
22 words
The process as set forth in claim 32 wherein the inert carrier is taken from the group of helium, argon, or nitrogen.
Claim 43
Dependent Claim
39 words
The process as set forth in claim 32 wherein at least one taken from the group of CF 4 , F 2 , C 2 F 6 , NF 3 , and CHF 3 is added to said gas.
Claim 44
Dependent Claim
56 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) generating at least free radicals from a gas comprised of SF 6 and an inert carrier in a plasma generator remote from a process chamber; and (b) introducing said gas and a source of hydrogen into said chamber and to said film.
Claim 45
Dependent Claim
56 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) generating at least free radicals from a gas comprised of SF 6 and an inert carrier in a plasma generator remote from a process chamber; and (b) introducing said gas and a source of hydrogen into said chamber and to said film.
Claim 46
Dependent Claim
22 words
The process as set forth in claim 40 wherein said source of hydrogen is added to said gas inside said process chamber.
Claim 47
Dependent Claim
25 words
The process as set forth in claim 40 wherein said source of hydrogen is added to said gas before generating said at least free radicals.
Claim 48
Dependent Claim
25 words
The process as set forth in claim 40 wherein said source of hydrogen is added to said gas after generating said at least free radicals.
Claim 49
Dependent Claim
33 words
The process as set forth in claim 40 wherein at least one taken from the group of CF 4 , F 2 , and C 2 F 6 is added to said gas.
Claim 50
Dependent Claim
39 words
The process as set forth in claim 40 wherein at least one taken from the group of CF 4 , F 2 , C 2 F 6 , NF 3 , and CHF 3 is added to said gas.
Claim 51
Dependent Claim
36 words
The process as set forth in claim 40 wherein the hydrogen source is taken from the group of CH 4 , H 2 , NH 3 , hydrocarbon or any molecule with an abstractable hydrogen atom.
Claim 52
Dependent Claim
22 words
The process as set forth in claim 40 wherein the inert carrier is taken from the group of helium, argon, or nitrogen.
Claim 53
Dependent Claim
17 words
The process as set forth in claim 40 wherein the process is carried out at 200° C.
Claim 54
Dependent Claim
37 words
The process as set forth in claim 40 wherein the low pressure is 0.915 Torr and wherein the mixture has flow comprised of Helium at 2200 sccm, hydrogen at 68 sccm, and SF 6 at 27.5 sccm.
Claim 55
Dependent Claim
102 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) generating at least free radicals from a gas comprised of SF 6 and a gas taken from the group of CF 4 , F 2 , and C 2 F 6 and an inert carrier taken from the group of helium, argon, or nitrogen in a plasma generator remote from the process chamber; and (b) introducing said gas and a source of hydrogen taken from the group of CH 4 , H 2 , NH 3 , hydrocarbon or any molecule with an abstractable hydrogen atom said film.
Claim 56
Dependent Claim
102 words
A process for etch of a Silicon Nitride film comprising the steps of: (a) generating at least free radicals from a gas comprised of SF 6 and a gas taken from the group of CF 4 , F 2 , and C 2 F 6 and an inert carrier taken from the group of helium, argon, or nitrogen in a plasma generator remote from the process chamber; and (b) introducing said gas and a source of hydrogen taken from the group of CH 4 , H 2 , NH 3 , hydrocarbon or any molecule with an abstractable hydrogen atom said film.
Claim 57
Dependent Claim
22 words
The process as set forth in claim 50 wherein said source of hydrogen is added to said gas inside said process chamber.
Claim 58
Dependent Claim
25 words
The process as set forth in claim 50 wherein said source of hydrogen is added to said gas before generating said at least free radicals.
Claim 59
Dependent Claim
25 words
The process as set forth in claim 50 wherein said source of hydrogen is added to said gas after generating said at least free radicals.
Claim 60
Dependent Claim
17 words
The process as set forth in claim 50 wherein the process is carried out at 200° C.
Claim 61
Dependent Claim
38 words
The process as set forth in claim 50 wherein the low pressure is 0.915 Torr and wherein the mixture has a flow comprised of Helium at 2200 sccm, hydrogen at 68 sccm, and SF 6 at 27.5 sccm.
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) | 1992-08-14 | 1993-02-13 | 1993-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-14 | 1997-02-13 | 1997-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-14 | 2001-02-13 | 2001-08-15 | $7700.00 | Window Closed / Lapsed |