US5536364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of plasma etching silicon
Assignee: Denso Corp
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Filing: 1994-06-03
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Granted: 1996-07-16
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Expires: 2014-06-03
Abstract
Abstract A plasma etching process for forming a recess or opening on a silicon substrate by generating plasma between a pair of electrodes in an anode-coupled planar-type plasma etching apparatus and etching the silicon substrate located on one of the electrodes with the plasma, an improvement residing in that an etchant is a mixed gas of sulfur hexafluoride and oxygen and an etching mask covering the substrate, except for a portion where the recess or opening is to be formed, is made of chromium or a chromium compound. Preferably the distance between the electrodes is 10 to 30 mm, the volume ratio of sulfur hexafluoride to oxygen is 90:10 to 60:40, the pressure of the etchant gas is 0.15 to 0.4 Torr (20 to 53 Pa), and the temperature of the substrate is not less than 40 DEG C.
Inventors
- 👤 Takahiko Yoshida
- 👤 Kazushi Asami
- 👤 Muneo Yorinaga
- 👤 Yoshimi Yoshino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:33
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/69; H10P50/691; H10P50/692; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/945
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
A plasma etching process for forming a recess in a silicon substrate, comprising: generating plasma between a pair of electrodes in an anode-coupled planar-type plasma etching apparatus; providing an etching mask covering said silicon substrate except for a portion of said silicon substrate where said recess is to be formed, said etching mask being made of one of chromium and a chromium compound; and etching said silicon substrate arranged on one of said electrodes with said plasma, wherein an etchant gas is a mixed gas of sulfur hexaflouride and oxygen, a volume ratio of said sulfur hexaflouride to said oxygen is in a range from 90:10 to 70:30, said etchant gas is kept at a pressure in a range from 0.15 to 0.4 Torr, and said substrate is kept at a temperature of not less than 40° C.
Claim 2
Dependent Claim
138 words
A plasma etching process for forming a recess in a silicon substrate, comprising: generating plasma between a pair of electrodes in an anode-coupled planar-type plasma etching apparatus; providing an etching mask covering said silicon substrate except for a portion of said silicon substrate where said recess is to be formed, said etching mask being made of one of chromium and a chromium compound; and etching said silicon substrate arranged on one of said electrodes with said plasma, wherein an etchant gas is a mixed gas of sulfur hexaflouride and oxygen, a volume ratio of said sulfur hexaflouride to said oxygen is in a range from 90:10 to 70:30, said etchant gas is kept at a pressure in a range from 0.15 to 0.4 Torr, and said substrate is kept at a temperature of not less than 40° C.
Claim 3
Dependent Claim
20 words
A process according to claim 1, wherein a pressure of said etchant gas is maintained at less than 53 Pa.
Claim 4
Dependent Claim
18 words
A process according to claim 1, wherein a temperature of said substrate is kept greater than 60° C.
Claim 5
Dependent Claim
146 words
A plasma etching process for forming a recess in a silicon substrate, comprising: generating plasma between a pair of electrodes in an anode-coupled planar-type plasma etching apparatus; providing an etching mask covering said substrate except for a portion where said recess is to be formed, said etching mask being made of one of chromium and a chromium compound; and etching said silicon substrate arranged on one of said electrodes with said plasma, wherein an etchant gas is a mixed gas of sulfur hexaflouride and oxygen, said etchant gas is kept at a pressure in a range from 0.15 to 0.4 Torr, said electrodes are arranged with a distance therebetween of 10 to 30 mm, a volume ratio of said sulfur hexaflouride to said oxygen is in a range from 90:10 to 60:40, and said substrate is kept at a temperature of not less than 40° C.
Claim 6
Dependent Claim
146 words
A plasma etching process for forming a recess in a silicon substrate, comprising: generating plasma between a pair of electrodes in an anode-coupled planar-type plasma etching apparatus; providing an etching mask covering said substrate except for a portion where said recess is to be formed, said etching mask being made of one of chromium and a chromium compound; and etching said silicon substrate arranged on one of said electrodes with said plasma, wherein an etchant gas is a mixed gas of sulfur hexaflouride and oxygen, said etchant gas is kept at a pressure in a range from 0.15 to 0.4 Torr, said electrodes are arranged with a distance therebetween of 10 to 30 mm, a volume ratio of said sulfur hexaflouride to said oxygen is in a range from 90:10 to 60:40, and said substrate is kept at a temperature of not less than 40° C.
Claim 7
Dependent Claim
20 words
A process according to claim 4, wherein a pressure of said etchant gas is maintained at less than 53 Pa.
Claim 8
Dependent Claim
18 words
A process according to claim 4, wherein a temperature of said substrate is kept greater than 60° C.
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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) | 1999-07-16 | 2000-01-15 | 2000-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-16 | 2004-01-15 | 2004-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-16 | 2008-01-15 | 2008-07-16 | $7700.00 | Window Closed / Lapsed |