US6265285B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a self-aligned trench isolation
Assignee: Vanguard International Semiconductor Corp
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Filing: 2000-10-25
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Granted: 2001-07-24
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Expires: 2020-10-25
Abstract
Abstract A method of forming a self-aligned trench isolation comprises forming a silicon film on a pad oxide that is grown upon a semiconductor substrate, and then etching the silicon film to expose the pad oxide and form a first opening. A poly-oxide is grown up by thermal process to cover on the silicon film and form a second opening with a width smaller than that of the first opening, and then the poly-oxide is etched back to form a poly-oxide spacer. In the formation of the poly-oxide spacer, the pad oxide is also etched to expose the semiconductor substrate. After a trench is formed into the semiconductor substrate through the second opening, a dielectric film is deposited and filled in the trench, and then etched back to expose the silicon film and leave the portion of the dielectric film inside the trench. The silicon film is then removed to form the resultant trench isolation.
Inventors
- 👤 Horng-Huei Tseng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:53
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/10; H10W10/17
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
137 words
A method of forming a self-aligned trench isolation on a semiconductor substrate with a pad oxide thereon, the method comprising the steps of: depositing a silicon film on said pad oxide; selectively removing said silicon film to expose said pad oxide, leave a residue silicon film, and form a first opening in said residue silicon film; forming a poly-oxide layer covered on said residue silicon film and a second opening between said poly-oxide layer; selectively removing said poly-oxide layer and pad oxide to form a poly-oxide spacer and expose said semiconductor substrate through said second opening; forming a trench extending into said semiconductor substrate through said second opening; depositing a dielectric film to fill in said trench and second opening; selectively removing said dielectric film to expose said residue silicon film; and removing said residue silicon film.
Claim 2
Independent Claim
137 words
A method of forming a self-aligned trench isolation on a semiconductor substrate with a pad oxide thereon, the method comprising the steps of: depositing a silicon film on said pad oxide; selectively removing said silicon film to expose said pad oxide, leave a residue silicon film, and form a first opening in said residue silicon film; forming a poly-oxide layer covered on said residue silicon film and a second opening between said poly-oxide layer; selectively removing said poly-oxide layer and pad oxide to form a poly-oxide spacer and expose said semiconductor substrate through said second opening; forming a trench extending into said semiconductor substrate through said second opening; depositing a dielectric film to fill in said trench and second opening; selectively removing said dielectric film to expose said residue silicon film; and removing said residue silicon film.
Claim 3
Dependent Claim
15 words
A method according to claim 1 , wherein said silicon film is a polycrystalline silicon.
Claim 4
Dependent Claim
15 words
A method according to claim 1 , wherein said silicon film is an amorphous silicon.
Claim 5
Dependent Claim
16 words
A method according to claim 1 , wherein said first opening is formed by plasma etch.
Claim 6
Dependent Claim
20 words
A method according to claim 1 , wherein said poly-oxide layer is formed by thermally oxidizing said residue silicon film.
Claim 7
Dependent Claim
16 words
A method according to claim 1 , wherein said poly-oxide spacer is formed by directional etch.
Claim 8
Dependent Claim
15 words
A method according to claim 1 , wherein said trench is formed by plasma etch.
Claim 9
Dependent Claim
15 words
A method according to claim 1 , wherein said dielectric film is a silicon dioxide.
Claim 10
Dependent Claim
16 words
A method according to claim 1 , wherein said dielectric film is etched back by CMP.
Claim 11
Dependent Claim
17 words
A method according to claim 1 , wherein said residue silicon film is removed by dry etch.
Claim 12
Dependent Claim
17 words
A method according to claim 1 , wherein said residue silicon film is removed by wet etch.
Claim 13
Dependent Claim
24 words
A method according to claim 1 further comprising the steps of: removing said pad oxide; and forming a gate oxide on said semiconductor substrate.
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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) | 2004-07-23 | 2005-01-22 | 2005-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-07-23 | 2009-01-22 | 2009-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-07-23 | 2013-01-22 | 2013-07-24 | $7700.00 | Window Closed / Lapsed |