US5326727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for integrated circuit fabrication including linewidth control during etching
Assignee: Nokia Bell Labs
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Filing: 1992-12-30
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Granted: 1994-07-05
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Expires: 2012-12-30
Abstract
Abstract Pattern transfer from a resist to an underlying layer is accomplished by etching the underlying layer in a plasma comprising hydrogen bromide and oxygen. Accuracy of pattern transfer is obtained by using first and second materials underneath the resist. The first and second materials may be, e.g., polysilicon and a photoresist. Etching of the resist is performed under conditions designed to minimize changes in the horizontal dimensions.
Inventors
- 👤 Taeho Kook
- 👤 Avinoam Kornblit
- 👤 Kolawole R. Olasupo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:34
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; H10P50/71
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
A method of integrated circuit fabrication comprising the steps of: forming a layer of first material on a substrate; covering said layer of first material with a layer of second material of photoresist, said second layer being a planarizing layer; covering said layer of second material with a resist, said second material reducing reflections of radiation used in the selective exposure of said resist; selectively exposing portions of said resist to radiation; etching said planarizing layer in a plasma comprising oxygen and at least one member selected from the group consisting of halogens and halogen hydrides, said at least one member and said oxygen having concentrations selected to minimize changes in the dimensions of the resist during etching which exposes portions of said material.
Claim 2
Independent Claim
124 words
A method of integrated circuit fabrication comprising the steps of: forming a layer of first material on a substrate; covering said layer of first material with a layer of second material of photoresist, said second layer being a planarizing layer; covering said layer of second material with a resist, said second material reducing reflections of radiation used in the selective exposure of said resist; selectively exposing portions of said resist to radiation; etching said planarizing layer in a plasma comprising oxygen and at least one member selected from the group consisting of halogens and halogen hydrides, said at least one member and said oxygen having concentrations selected to minimize changes in the dimensions of the resist during etching which exposes portions of said material.
Claim 3
Dependent Claim
16 words
A method as recited in claim 1 in which said plasma further comprises an inert constituent.
Claim 4
Dependent Claim
14 words
A method as recited in claim 2 in which said inert constituent comprises helium.
Claim 5
Dependent Claim
14 words
A method as recited in claim 1 in which said first material comprises polysilicon.
Claim 6
Dependent Claim
15 words
A method as recited in claim 4 comprising the further step of etching said polysilicon.
Claim 7
Dependent Claim
23 words
A method as recited in claim 1 in which said at least one member is selected from the group consisting of hydrogen halides.
Claim 8
Dependent Claim
15 words
A method as recited in claim 6 in which said halogen hydride is hydrogen bromide.
Claim 9
Dependent Claim
21 words
A method as recited in claim 7 in which the concentration of said hydrogen bromide to said oxygen is approximately 1:1.
Claim 10
Dependent Claim
20 words
A method as recited in claim 8 in which said plasma has a pressure of approximately 25 mTorr or less.
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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) | 1997-07-04 | 1998-01-03 | 1998-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-04 | 2002-01-03 | 2002-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-04 | 2006-01-03 | 2006-07-05 | $7700.00 | Window Closed / Lapsed |