US4764483A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for burying a step in a semiconductor substrate
Assignee: Panasonic Holdings Corp
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Filing: 1987-08-06
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Granted: 1988-08-16
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Expires: 2007-08-06
Abstract
Abstract Disclosed is a method for burying a step in a semiconductor substrate in which (1) SiO 2 layer is formed on a lower part of the step, (2) photoresist layer with equal thickness to the height of the step on the SiO 2 layer at a portion corresponding to the lower part of the step, (3) sputter-SiO 2 layer is formed by sputtering on the photoresist layer and SiO 2 layer, (4) another photoresist layer is formed on the sputter-SiO 2 layer, (5) the another photoresist layer and sputter-SiO 2 layer are removed, and (6) the SiO 2 layer and photoresist layer are removed. By this method, semiconductor substrate with flatness of within 50 nm in a 6-inch wafer can be obtained.
Inventors
- 👤 Genshu Fuse
- 👤 Kenji Tateiwa
- 👤 Ichiro Nakao
- 👤 Hideaki Shimoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:54
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/06; H10P95/062; H10P95/064; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
92 words
A method for burying a step in a semiconductor substrate comprising: forming a first film on a lower part and upper part of said step; forming a photoresist layer with substantially equal thickness to the height of said step on said first film at a portion corresponding to said lower part of said step; forming a second film on said photoresist layer and said first film; forming a third film substantially flatly on said second film; removing said third and second films by etching; and removing said first film and photoresist layer.
Claim 2
Independent Claim
92 words
A method for burying a step in a semiconductor substrate comprising: forming a first film on a lower part and upper part of said step; forming a photoresist layer with substantially equal thickness to the height of said step on said first film at a portion corresponding to said lower part of said step; forming a second film on said photoresist layer and said first film; forming a third film substantially flatly on said second film; removing said third and second films by etching; and removing said first film and photoresist layer.
Claim 3
Dependent Claim
27 words
A method of claim 1, wherein said first film is an oxide layer, second film is a thin oxide layer and third film is a photoresist layer.
Claim 4
Dependent Claim
15 words
A method of claim 2, wherein said first and second films are SiO 2 layers.
Claim 5
Dependent Claim
18 words
A method of claim 2, wherein said second film is formed by a sputtering or plasma deposition technique.
Claim 6
Dependent Claim
22 words
A method of claim 1, further comprising a step of forming a channel stopper region in said lower part of said step.
Claim 7
Dependent Claim
21 words
A method of claim 1, further comprising a step of forming a semiconductor device in said upper part of said step.
Claim 8
Independent Claim
107 words
A method for burying a step in a semiconductor substrate comprising: forming a SiO 2 layer on a lower part and upper part of said step; forming a first photoresist layer with substantially equal thickness to the height of said step on said SiO 2 layer at a portion corresponding to said lower part of said step; forming a sputter-SiO 2 layer on said photoresist pattern and said SiO 2 layer by sputtering technique; forming a second photoresist layer substantially flatly on said sputter-SiO 2 layer; removing said second photoresist layer and sputter-SiO 2 layer by etching; and removing said SiO 2 layer and first photoresist layer.
Claim 9
Independent Claim
107 words
A method for burying a step in a semiconductor substrate comprising: forming a SiO 2 layer on a lower part and upper part of said step; forming a first photoresist layer with substantially equal thickness to the height of said step on said SiO 2 layer at a portion corresponding to said lower part of said step; forming a sputter-SiO 2 layer on said photoresist pattern and said SiO 2 layer by sputtering technique; forming a second photoresist layer substantially flatly on said sputter-SiO 2 layer; removing said second photoresist layer and sputter-SiO 2 layer by etching; and removing said SiO 2 layer and first photoresist layer.
Claim 10
Independent Claim
115 words
A method for burying a step in a semiconductor substrate comprising: forming a channel stopper region in a lower part of said step; forming a first film on said lower part and upper part of said step; forming a photoresist layer with substantially equal thickness to the height of said step on said first film at a portion corresponding to said lower part of said step; forming a second film on said photoresist pattern and said first film; forming a third film substantially flatly on said second film; removing said third and second films by etching; removing said first film and photoresist layer; and forming a semiconductor device in said upper part of said step.
Claim 11
Independent Claim
115 words
A method for burying a step in a semiconductor substrate comprising: forming a channel stopper region in a lower part of said step; forming a first film on said lower part and upper part of said step; forming a photoresist layer with substantially equal thickness to the height of said step on said first film at a portion corresponding to said lower part of said step; forming a second film on said photoresist pattern and said first film; forming a third film substantially flatly on said second film; removing said third and second films by etching; removing said first film and photoresist layer; and forming a semiconductor device in said upper part of said step.
References Cited (Backward Citations)
US3976524A
Cited
US4274909A
Cited
US4389281A
Cited
US4402851A
Cited
JPS57204135A
Cited
US4506434A
Cited
US4505025A
Cited
JPS59129438A
Cited
JPS59167030A
Cited
US4662986A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |