US4662989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency metal lift-off process
Assignee: Samsung Electronics Co Ltd
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Filing: 1985-10-04
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Granted: 1987-05-05
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Expires: 2005-10-04
Abstract
Abstract An improved high efficiency metal lift-off process for removing a layer of metal at least partially covering a layer of photoresist. The method comprises forming microcracks located above the layer of photoresist in the layer of metal to be removed and providing solvent to the layer of photoresist through the microcracks.
Inventors
- 👤 Daniel K. Casey
- 👤 Eddie C. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:20
CPC Classifications
H; H10; H10W; H10W90/00; H10P; H10P76/00; H10P76/20; H10P76/202; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/058; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/948; Y10S438/951
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
73 words
A high efficiency metal lift-off process for removing a layer of metal at least partially covering a layer of photoresist, the process comprising: applying an additional layer of material over the layer of metal to be removed so that the additional layer of material causes microcracks to develop through both the layer of metal to be removed and the additional layer of material; and providing solvent to the photoresist layer through the microcracks.
Claim 2
Dependent Claim
73 words
A high efficiency metal lift-off process for removing a layer of metal at least partially covering a layer of photoresist, the process comprising: applying an additional layer of material over the layer of metal to be removed so that the additional layer of material causes microcracks to develop through both the layer of metal to be removed and the additional layer of material; and providing solvent to the photoresist layer through the microcracks.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein the additional layer of material comprises a metal.
Claim 4
Dependent Claim
24 words
The process of claim 2 wherein the additional layer of material comprises a metal selected from the group consisting of Cr, TiW, and W.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the additional layer of material comprises a dielectric.
Claim 6
Dependent Claim
97 words
A high efficiency metal lift-off process for removing a layer of metal at least partially covering a layer of photoresist, the layer of metal to be removed having a stress in a first predetermined direction, the method, comprising: depositing an additional layer of material over the layer of metal to be removed, the additional layer of material having a stress in a direction substantially opposite to the first predetermined direction, thus forming microcracks through both the metal layer to be removed and the additional layer of material; and providing solvent to the photoresist layer through the microcracks.
Claim 7
Dependent Claim
97 words
A high efficiency metal lift-off process for removing a layer of metal at least partially covering a layer of photoresist, the layer of metal to be removed having a stress in a first predetermined direction, the method, comprising: depositing an additional layer of material over the layer of metal to be removed, the additional layer of material having a stress in a direction substantially opposite to the first predetermined direction, thus forming microcracks through both the metal layer to be removed and the additional layer of material; and providing solvent to the photoresist layer through the microcracks.
Claim 8
Dependent Claim
37 words
The process of claim 5 wherein the level of stress in the additional layer of material is at least one order of magnitude greater than the level of stress in the layer of metal to be removed.
Claim 9
Dependent Claim
14 words
The process of claim 6 wherein the additional layer of material comprises a metal.
Claim 10
Dependent Claim
24 words
The process of claim 7 wherein the additional layer of material comprises a metal selected from the group consisting of Cr, TiW, and W.
Claim 11
Dependent Claim
14 words
The process of claim 6 wherein the additional layer of material comprises a dielectric.
Claim 12
Dependent Claim
14 words
The process of claim 5 wherein the additional layer of material comprises a metal.
Claim 13
Dependent Claim
24 words
The process of claim 10 wherein the additional layer of material comprises a metal selected from the group consisting of Cr, TiW, and W.
Claim 14
Dependent Claim
14 words
The process of claim 5 wherein the additional layer of material comprises a dielectric.
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) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |