US5264076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit process using a "hard mask"
Assignee: Nokia Bell Labs
•
Filing: 1992-12-17
•
Granted: 1993-11-23
•
Expires: 2012-12-17
Abstract
Abstract A layer of spin-on-glass is used as a hard mask for patterning an underlying layer of polysilicon. The patterned polysilicon may be used in the gate structures of field effect transistors.
Inventors
- 👤 John D. Cuthbert
- 👤 David P. Favreau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:00
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/71
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A method of integrated circuit fabrication comprising the steps of: forming features on a substrate, said features having topography; forming a layer of material covering said features; forming a layer of nonconformal material on said layer of material; forming a layer of resist on said layer of nonconformal material; patterning said resist and said layer of nonconformal material; removing said layer of resist; and patterning said layer of material using said layer of nonconformal material as an etch mask.
Claim 2
Independent Claim
79 words
A method of integrated circuit fabrication comprising the steps of: forming features on a substrate, said features having topography; forming a layer of material covering said features; forming a layer of nonconformal material on said layer of material; forming a layer of resist on said layer of nonconformal material; patterning said resist and said layer of nonconformal material; removing said layer of resist; and patterning said layer of material using said layer of nonconformal material as an etch mask.
Claim 3
Dependent Claim
15 words
A method as recited in claim 1 in which said layer of material comprises polysilicon.
Claim 4
Dependent Claim
17 words
A method as recited in claim 1 in which said layer of nonconformal material comprises a spin-on-glass.
Claim 5
Dependent Claim
17 words
A method as recited in claim 3 further comprising the step of removing said layer of spin-on-glass.
Claim 6
Dependent Claim
19 words
A method as recited in claim 4 in which said removing step comprises using a solution comprising HF acid.
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) | 1996-11-22 | 1997-05-24 | 1997-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-22 | 2001-05-24 | 2001-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-22 | 2005-05-24 | 2005-11-23 | $7700.00 | Window Closed / Lapsed |