US5096850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of laser trimming
Assignee: Intersil Corp
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Filing: 1991-04-23
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Granted: 1992-03-17
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Expires: 2011-04-23
Abstract
Abstract A method including covering the area to be laser trimmed with a first insulative layer having a thickness sufficiently thin that a layer can trim the area through the first insulative layer. An etch stop is formed on the first insulative layer over the area to be trimmed and covered with a second insulative layer. A portion of the second insulative layer is etched to expose the etch stop and a portion of the etch stop is then removed to expose a portion of the first insulative layer and laser trimming is conducted through the exposed first insulative layer. The etch stop is part of a first level of interconnects made of the same material and simultaneously with the etch stop. The area to be trimmed is part of a second level of contacts that interconnect another second material.
Inventors
- 👤 Maxwell W. Lippitt, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:38
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/066; H10W20/067; H10W20/068; Y; Y10; Y10S; Y10S148/00; Y10S148/093; Y10S438/00; Y10S438/94
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
125 words
A method of laser trimming areas of an integrated circuit comprising: covering a substrate including an area to be laser trimmed with a first insulative layer having a thickness sufficiently thin that a laser can trim said area through said first insulative layer; forming an etch stop of a first material over said area; covering said first insulative layer and said etch stop with a second insulative layer; etching a portion of said second insulative layer to said etch stop to expose at least a portion of said etch stop; removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area; and laser trimming said area through said exposed portion of said first insulative layer.
Claim 2
Independent Claim
125 words
A method of laser trimming areas of an integrated circuit comprising: covering a substrate including an area to be laser trimmed with a first insulative layer having a thickness sufficiently thin that a laser can trim said area through said first insulative layer; forming an etch stop of a first material over said area; covering said first insulative layer and said etch stop with a second insulative layer; etching a portion of said second insulative layer to said etch stop to expose at least a portion of said etch stop; removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area; and laser trimming said area through said exposed portion of said first insulative layer.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein said area to be laser trimmed is a semiconductor portion of said substrate.
Claim 4
Dependent Claim
21 words
A method according to claim 2, wherein said area to be laser trimmed is part of an array of a memory.
Claim 5
Dependent Claim
24 words
A method according to claim 1, wherein a first level of interconnects of said first material are formed simultaneously with forming said etch stop.
Claim 6
Dependent Claim
38 words
A method according to claim 4, wherein said area to be laser trimmed is part of a second level of contacts and interconnects of a second material and separated from said etch stop by said first insulative layer.
Claim 7
Dependent Claim
64 words
A method according to claim 4, including removing portions of said second insulative layer to expose portion of said first level interconnects; including forming a third level of interconnect on said second insulative layer and contacting said exposed portion of said first interconnect level; and subsequently removing said portion of said second insulative layer to expose said etch stop and removing said etch stop.
Claim 8
Dependent Claim
54 words
A method according to claim 6 wherein said third interconnect level is formed of a third material and removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area is performed selectively so as not to etch exposed portions of said third interconnect level.
Claim 9
Dependent Claim
106 words
A method according to claim 4, including forming a third level of interconnects of a third material on said second insulative layer; including covering said third level of interconnects with a third insulative layer; wherein removing a Portion of said second insulative layer to expose said etch stop includes removing portions of said third insulative layer to expose said etch stop and portions of said third interconnect level; and wherein removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area is performed selectively so as not to etch exposed portions of said third interconnect level.
Claim 10
Dependent Claim
106 words
A method according to claim 1, including forming a third level of interconnects of a third material on said second insulative layer; including covering said third level of interconnects with a third insulative layer; wherein removing a portion of said second insulative layer to expose said etch stop includes removing portions of said third insulative layer to expose said etch stop and portions of said third interconnect level; and wherein removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area is performed selectively so as not to etch exposed portions of said third interconnect level.
Claim 11
Dependent Claim
28 words
A method according to claim 9, wherein said first and third materials are metals and said area to be laser trimmed is a polycrystalline semiconductor on said substrate.
Claim 12
Dependent Claim
36 words
A method according to claim 1, wherein said said etch stop is formed to have a greater lateral area than the area to be laser trimmed and only a portion of said etch stop is removed.
Claim 13
Independent Claim
96 words
A method of laser trimming areas of an integrated circuit having an etch stop separated from an area to be laser trimmed by a first insulative layer and said etch stop being covered by a second insulative layer, comprising: etching a portion of said second insulative layer to said etch stop to expose at least a portion of said etch stop; removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area; and laser trimming said area through said exposed portion of said first insulative layer.
Claim 14
Independent Claim
96 words
A method of laser trimming areas of an integrated circuit having an etch stop separated from an area to be laser trimmed by a first insulative layer and said etch stop being covered by a second insulative layer, comprising: etching a portion of said second insulative layer to said etch stop to expose at least a portion of said etch stop; removing at least a portion of said etch stop to expose a portion of said first insulative layer above said area; and laser trimming said area through said exposed portion of said first insulative layer.
References Cited (Backward Citations)
US4764485A
Cited
US4960729A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-17 | 1995-09-16 | 1996-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-17 | 1999-09-16 | 2000-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-17 | 2003-09-16 | 2004-03-17 | $7700.00 | Window Closed / Lapsed |