Patent US4807013A successfully refreshed from Google Patents.
US4807013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polysilicon fillet
Assignee: Nokia Bell Labs
•
Filing: 1987-04-08
•
Granted: 1989-02-21
•
Expires: 2007-04-08
Abstract
Abstract Disclosed is an integrated circuit manufacturing technique that relies on the use of polysilicon fillets for overcoming the well known adverse effects of steep sidewalls produced by anisotropic etching processes and undercuts produced by anisotropic etching of multilayers.
Inventors
- 👤 Ajit S. Manocha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:35
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/40; H10P76/408; H10P76/4085; H10D; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/518; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/40; H10W20/41; H10W20/44; H10W20/4451; Y; Y10; Y10S; Y10S257/00; Y10S257/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
Device comprising: a silicon substrate a plurality of layers covering the substrate, at least one of which is a patterned polysilicon layer resulting in a steep sidewall portion, a polysilicon fillet in the corner formed by the steep sidewall and the layer supporting it, said fillet and said polysilicon layer forming an interface, said fillet having a rounded surface, and at least one additional layer covering the polysilicon layer and the polysilicon fillet.
Claim 2
Dependent Claim
73 words
Device comprising: a silicon substrate a plurality of layers covering the substrate, at least one of which is a patterned polysilicon layer resulting in a steep sidewall portion, a polysilicon fillet in the corner formed by the steep sidewall and the layer supporting it, said fillet and said polysilicon layer forming an interface, said fillet having a rounded surface, and at least one additional layer covering the polysilicon layer and the polysilicon fillet.
Claim 3
Dependent Claim
60 words
Device comprising: a silicon substrate, a dielectric layer covering at least portions of the substrate, a polysilicon conductor formed on the dielectric layer, said polysilicon conductor having at least one essentially vertical sidewall, a polysilicon fillet having a rounded surface and an interface with said conductor in the corner formed by the esentially vertical sidewall and the underlying dielectric layer.
Claim 4
Dependent Claim
60 words
Device comprising: a silicon substrate, a dielectric layer covering at least portions of the substrate, a polysilicon conductor formed on the dielectric layer, said polysilicon conductor having at least one essentially vertical sidewall, a polysilicon fillet having a rounded surface and an interface with said conductor in the corner formed by the esentially vertical sidewall and the underlying dielectric layer.
Claim 5
Dependent Claim
19 words
Device of claim 2 including an additional dielectric layer covering the first recited dielectric layer and the polysilicon fillet.
Claim 6
Dependent Claim
12 words
Device of claim 3 in which the dielectric layers comprise silicon dioxide.
Claim 7
Dependent Claim
32 words
A device as recited in claim 1 in which one of said plurality of layers comprises at least one member selected from the group consisting of refractory metals and refractory metal silicides.
Claim 8
Dependent Claim
22 words
A device as recited in claim 1 in which at least two layers of said plurality are patterned to form steep sidewalls.
Claim 9
Dependent Claim
19 words
A device as recited in claim 6 in which said at least two layers comprise polysilicon and a dielectric.
Claim 10
Dependent Claim
14 words
A device as recited in claim 7 in which said dielectric comprises silicon dioxide.
References Cited (Backward Citations)
US4234362A
Cited
US4329706A
Cited
US4406051A
Cited
US4312680A
Cited
US4319261A
Cited
US4691435A
Cited
US4374700A
Cited
US4419809A
Cited
US4507171A
Cited
US4507853A
Cited
US4478679A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |