US5292402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Masking material for applications in plasma etching
Assignee: National Semiconductor Corp
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Filing: 1992-07-09
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Granted: 1994-03-08
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Expires: 2012-07-09
Abstract
Abstract Materials of the lead perovskite family PbZr x Ti 1-x O 3 have been discovered to be excellent masking materials in the etching of silicon and silicon-containing materials with chlorine and fluorine -based plasmas. Generally, materials of the lead perovskite family are suitable masking materials for any material that is etched in chlorine and fluorine -based plasmas.
Inventors
- 👤 Norman E. Abt
- 👤 Sheldon Aronowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:08
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/69; H10P50/691; H10P50/692; Y; Y10; Y10S; Y10S148/00; Y10S148/106
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
70 words
A method for etching a body using a fluorine or chlorine-based plasma etch, comprising the steps of: forming a first layer of material selected from the lead perovskite family over the body; forming a patterned masking layer over the first layer; forming a patterned first layer by etching the first layer through the masking layer; and etching the body through the patterned first layer using a fluorine or chlorine-based plasma.
Claim 2
Independent Claim
70 words
A method for etching a body using a fluorine or chlorine-based plasma etch, comprising the steps of: forming a first layer of material selected from the lead perovskite family over the body; forming a patterned masking layer over the first layer; forming a patterned first layer by etching the first layer through the masking layer; and etching the body through the patterned first layer using a fluorine or chlorine-based plasma.
Claim 3
Dependent Claim
15 words
A method as in claim 1 wherein said etching step is a reactive ion etch.
Claim 4
Dependent Claim
17 words
A method as in claim 1 wherein said etching step is performed in a parallel plate reactor.
Claim 5
Dependent Claim
30 words
A method as in claim 1 wherein said first layer forming step comprising the step of adding a dopant or modifier to the material selected from the lead perovskite family.
Claim 6
Dependent Claim
13 words
A method as in claim 4 wherein the dopant or modifier is lanthanum.
Claim 7
Dependent Claim
44 words
A method as in claim 1 wherein the masking layer comprises photoresist, and wherein the patterned first layer forming step comprises the step of etching the first layer through windows in the masking layer using a hydrogen fluoride (HF) or hydrogen chloride (HCl) dip.
Claim 8
Dependent Claim
25 words
A method as in claim 1 further comprising the step of forming a barrier layer over the body prior to said first layer forming step.
Claim 9
Dependent Claim
13 words
A method as in claim 7 wherein the barrier layer is silicon dioxide.
Claim 10
Dependent Claim
41 words
A method as in claim 1 further comprising the step, following said body etching step, of removing the first layer using a sulfuric peroxide (H 2 SO 4 /H 2 O 2 ) hydrogen fluoride (HF), or hydrogen chloride (HCl) dip.
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) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |