US4734157A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective and anisotropic dry etching
Assignee: International Business Machines Corp
•
Filing: 1987-03-18
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Granted: 1988-03-29
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Expires: 2007-03-18
Abstract
Abstract A composition and method for anistropically etching polysilicon or silicides with excellent selectivity to an underlying layer of an oxide or nitride of silicon is disclosed. A mixture of CClF 3 or CCl 2 F 2 and ammonia is employed at moderate pressures in a reactive ion etching chamber.
Inventors
- 👤 Susanna R. Carbaugh
- 👤 Hung Y. Ng
- 👤 Murty S. Polavarapu
- 👤 David Stanasolovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:55
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
71 words
An anisotropic gas plasma process carried out in a reactive ion etching mode using an etchant gas for selectively patterned etching of an elemental silicon-containing layer overlying a covalent silicon-containing layer, which layers form a surface of a semiconductor device, wherein the etchant comprises a gaseous chlorofluorocarbon capable of supplying CFx and chlorine ions in admixture with 20-65% of ammonia by volume at a pressure of from 60 to 100 millitorr.
Claim 2
Dependent Claim
71 words
An anisotropic gas plasma process carried out in a reactive ion etching mode using an etchant gas for selectively patterned etching of an elemental silicon-containing layer overlying a covalent silicon-containing layer, which layers form a surface of a semiconductor device, wherein the etchant comprises a gaseous chlorofluorocarbon capable of supplying CFx and chlorine ions in admixture with 20-65% of ammonia by volume at a pressure of from 60 to 100 millitorr.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the chlorofluorocarbon is CClF 3 .
Claim 4
Dependent Claim
19 words
The process of claim 2 wherein the mass flow rate is in the range of 15 to 100 sccm.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein the elemental silicon-containing layer comprises silicon, polysilicon, or a refractory metal silicide.
Claim 6
Dependent Claim
17 words
The process of claim 4 wherein the covalent silicon-containing layer comprises an oxide or nitride of silicon.
Claim 7
Dependent Claim
16 words
The process of claim 3 wherein the elemental silicon-containing layer is N+ polysilicon or tungsten silicide.
Claim 8
Dependent Claim
13 words
The process of claim 6 wherein the covalent silicon-containing layer is silicon dioxide.
Claim 9
Dependent Claim
20 words
The process of claim 7 wherein the power density is in the range of 0.2 to 0.3 W/cm 2 .
Claim 10
Dependent Claim
18 words
The process of claim 1 wherein the mass flow rate is the range of 15 to 100 sccm.
Claim 11
Dependent Claim
18 words
The process of claim 1 wherein the elemental silicon-containing layer is silicon, polysilicon, or a refractory metal silicide.
Claim 12
Dependent Claim
17 words
The process of claim 1 wherein the covalent silicon-containing layer is an oxide or nitride of silicon.
Claim 13
Dependent Claim
16 words
The process of claim 1 wherein the elemental silicon-containing layer is N+ polysilicon or tungsten silicide.
Claim 14
Dependent Claim
13 words
The process of claim 1 wherein the covalent silicon-containing layer is silicon dioxide.
Claim 15
Dependent Claim
20 words
The process of claim 1 wherein the power density is in the range of 0.2 to 0.3 W/cm 2 .
Claim 16
Dependent Claim
64 words
An anisotropic gas plasma process carried out in a reactive ion etching mode using an etchant gas for patterned selective etching of an elemental silicon-containing layer overlying a covalent silicon-containing layer, which layers form a surface of a semiconductor device, wherein the etchant comprises CCl 2 F 2 in admixture with 20-65% of ammonia by volume at a pressure of 60 to 100 millitorr.
Claim 17
Dependent Claim
64 words
An anisotropic gas plasma process carried out in a reactive ion etching mode using an etchant gas for patterned selective etching of an elemental silicon-containing layer overlying a covalent silicon-containing layer, which layers form a surface of a semiconductor device, wherein the etchant comprises CCl 2 F 2 in admixture with 20-65% of ammonia by volume at a pressure of 60 to 100 millitorr.
Claim 18
Dependent Claim
19 words
The process of claim 15 wherein the mass flow rate is in the range of 30 to 60 sccm.
Claim 19
Dependent Claim
18 words
The process of claim 16 wherein the elemental silicon-containing layer comprises silicon, polysilicon, or a refractory metal silicide.
Claim 20
Dependent Claim
17 words
The process of claim 17 wherein the covalent silicon-containing layer comprises an oxide or nitride of silicon.
Claim 21
Dependent Claim
16 words
The process of claim 16 wherein the elemental silicon-containing layer is N+ polysilicon or tungsten silicide.
Claim 22
Dependent Claim
13 words
The process of claim 19 wherein the covalent silicon-containing layer is silicon dioxide.
Claim 23
Dependent Claim
20 words
The process of claim 20 wherein the power density is in the range of 0.125 to 0.3 W/cm 2 .
Claim 24
Dependent Claim
18 words
The process of claim 15 wherein the elemental silicon-containing layer is silicon, polysilicon, or a refractory metal silicide.
Claim 25
Dependent Claim
17 words
The process of claim 15 wherein the covalent silicon-containing layer is an oxide or nitride of silicon.
Claim 26
Dependent Claim
16 words
The process of claim 15 wherein the elemental silicon-containing layer is N+ polysilicon or tungsten silicide.
Claim 27
Dependent Claim
13 words
The process of claim 15 wherein the covalent silicon-containing layer is silicon dioxide.
Claim 28
Dependent Claim
20 words
The process of claim 15 wherein the power density is in the range of 0.125 to 0.3 W/cm 2 .
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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) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |