Patent US5418902A successfully refreshed from Google Patents.
Patent US5015331A successfully refreshed from Google Patents.
US5015331A
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Method of plasma etching with parallel plate reactor having a grid
Assignee: Matrix Integrated Systems Inc
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Filing: 1990-08-10
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Granted: 1991-05-14
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Expires: 2010-08-10
Abstract
Abstract A parallel plate reactor having a grounded grid disposed between an RF powered electrode and a grounded electrode upon which a substrate is disposed. A method of utilizing the above apparatus consists of etching the substrate using a composition of 30-100% NF 3 (nitrogen trifluoride) at 25 SCCM (standard cubic centimeter per minute) and 0-70% He (helium) at 75 SCCM to etch a layer of PECVD (plasma enchanced chemcial vapor deposition) Si 3 N 4 (silicon nitride). The etching takes place at 200 mtorr to 5 torr pressure and 50-400 watts RF power.
Inventors
- 👤 Gary B. Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:31
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
153 words
A method of etching a substrate comprising the steps of: placing the substrate on a surface in an apparatus comprising an upper electrode coupled to an R-F power source, a lower electrode and a grid having openings defined therein and disposed between said upper electrode and said lower electrode, said grid and upper electrode forming an upper chamber therebetween, said grid being clamped to have the same potential at all times as the lower electrode and forming with the lower electrode a lower chamber therebetween; passing a reactant gas into said upper chamber; subjecting said gas to an R-F field applied via said upper electrode to generate in said upper chamber a plasma including ions in said upper chamber; passing ions generated by said plasma through said grid toward said lower chamber; and etching said substrate on said surface, said surface being in said lower chamber, said substrate being etched by said ions.
Claim 2
Independent Claim
153 words
A method of etching a substrate comprising the steps of: placing the substrate on a surface in an apparatus comprising an upper electrode coupled to an R-F power source, a lower electrode and a grid having openings defined therein and disposed between said upper electrode and said lower electrode, said grid and upper electrode forming an upper chamber therebetween, said grid being clamped to have the same potential at all times as the lower electrode and forming with the lower electrode a lower chamber therebetween; passing a reactant gas into said upper chamber; subjecting said gas to an R-F field applied via said upper electrode to generate in said upper chamber a plasma including ions in said upper chamber; passing ions generated by said plasma through said grid toward said lower chamber; and etching said substrate on said surface, said surface being in said lower chamber, said substrate being etched by said ions.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said reactant gas comprises a fluorine source gas.
Claim 4
Dependent Claim
13 words
The method of claim 2 wherein said fluorine source gas comprises nitrogen trifluoride.
Claim 5
Dependent Claim
13 words
The method of claim 2 wherein said fluorine source gas comprises carbon tetraflouride.
Claim 6
Dependent Claim
13 words
The method of claim 2 wherein said fluorine source gas comprises sulfur hexafluoride.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the substrate comprises a semiconductor device.
Claim 8
Dependent Claim
14 words
The method of claim 6 wherein said reactant gas comprises a fluorine source gas.
Claim 9
Dependent Claim
13 words
The method of claim 7 wherein said fluorine source gas comprises nitrogen trifluoride.
Claim 10
Dependent Claim
13 words
The method of claim 7 wherein said fluorine source gas comprises carbon tetraflouride.
Claim 11
Dependent Claim
13 words
The method of claim 7 wherein said fluorine source gas comprises sulfur hexafluoride.
Claim 12
Dependent Claim
21 words
The method of claim 1 wherein said substrate includes a layer of silicon nitride and the reactant gas is nitrogen trifluoride.
Claim 13
Dependent Claim
23 words
The method of claim 11 in which said upper electrode is coupled to a power source in the range of approximately 50-400 watts.
Claim 14
Dependent Claim
13 words
The method of claim 12 wherein said power source is approximately 175 watts.
Claim 15
Dependent Claim
22 words
The method of claim 11 in which the nitrogen trifluoride concentration is in the of approximately 30-100% with the remainder being helium.
Claim 16
Dependent Claim
34 words
The method of claim 14 wherein the nitrogen, trifluoride concentration is approximately 50% with the remainder being helium and said helium is supplied at a rate of approximately 75 standard cubic centimeters per minute.
Claim 17
Dependent Claim
19 words
The method of claim 11 wherein said etching occurs in the range of 200 millitorr to 5 torr pressure.
Claim 18
Dependent Claim
13 words
The method of claim 16 wherein said etching occurs at approximately 600 millitorr.
Claim 19
Dependent Claim
21 words
The method of claim 1 wherein the substrate includes a layer comprising a low pressure chemical vapor deposition of silicon nitride.
Claim 20
Dependent Claim
23 words
The method of claim 18 in which said upper electrode is coupled to a power source in the range of approximately 50-150 watts.
Claim 21
Dependent Claim
13 words
The method of claim 19 wherein said power source is approximately 50 watts.
Claim 22
Dependent Claim
23 words
The method of claim 18 in which the nitrogen trifluoride concentration is in the range of approximately 20-80% with the remainder being oxygen.
Claim 23
Dependent Claim
34 words
The method of claim 21 wherein the nitrogen trifluoride concentration is approximately 67% with the remainder being oxygen and said oxygen is supplied at a rate of approximately 25 standard cubic centimeters per minute.
Claim 24
Dependent Claim
19 words
The method of claim 18 wherein said etching occurs in the range of 200 millitorr to 5 torr pressure.
Claim 25
Dependent Claim
13 words
The method of claim 23 wherein said etching occurs at approximately 500 millitorr.
Claim 26
Dependent Claim
15 words
The method of claim 18 wherein said lower electrode is cooled to approximately 60° C.
Claim 27
Dependent Claim
23 words
The method of claim 1 wherein the substrate includes a layer of an impurity doped oxide and the reactant gas is nitrogen trifluoride.
Claim 28
Dependent Claim
14 words
The method of claim 26 wherein said impurity doped oxide comprises phosphorous doped oxide.
Claim 29
Dependent Claim
14 words
The method of claim 26 wherein said impurity doped oxide comprises boron doped oxide.
Claim 30
Dependent Claim
23 words
The method of claim 26 in which said upper electrode is coupled to a power source in the range of approximately 50-400 watts.
Claim 31
Dependent Claim
13 words
The method of claim 29 wherein said power source is approximately 300 watts.
Claim 32
Dependent Claim
23 words
The method of claim 26 in which the nitrogen trifluoride concentration is in the range of approximately 30-100% with the remainder being helium.
Claim 33
Dependent Claim
34 words
The method of claim 31 wherein the nitrogen trifluoride concentration is approximately 50% with the remainder being helium and said helium is supplied at a rate of approximately 50 standard cubic centimeters per minute.
Claim 34
Dependent Claim
19 words
The method of claim 26 wherein said etching occurs in the range of 200 millitorr to 5 torr pressure.
Claim 35
Dependent Claim
13 words
The method of claim 33 wherein said etching occurs at approximately 1.5 torr.
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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) | 1994-05-13 | 1994-11-12 | 1995-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-13 | 1998-11-12 | 1999-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-13 | 2002-11-12 | 2003-05-14 | $7700.00 | Window Closed / Lapsed |