US5024896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collimated metal deposition
Assignee: International Business Machines Corp
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Filing: 1989-07-06
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Granted: 1991-06-18
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Expires: 2009-07-06
Abstract
Abstract A process and structure for depositing metal lines in a lift-off process is disclosed. The process comprises the deposition of a four-layer structure or lift-off stencil, comprising a first layer of a lift-off polymer etchable in oxygen plasma, a first barrier layer of hexamethyldisilizane (HMDS) resistant to an oxygen plasma, a second lift-off layer and a second barrier layer. Once these layers are deposited, a layer of photoresist is deposited and lithographically defined with the metal conductor pattern desired. The layers are then sequentially etched with oxygen and CF 4 , resulting in a dual overhang lift-off structure. Metal is then deposited by evaporation or sputtering through the lift-off structure. Following metal deposition, the stencil is lifted-off in a solvent such as N-methylpyrrolidone (NMP).
Inventors
- 👤 Gangadhara S. Mathad
- 👤 David Stanasolovich
- 👤 Giorgio G. Via
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:04
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/058; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12389; Y10T428/12396; Y10T428/12493; Y10T428/12528; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
105 words
A dual overhang, lift-off structure depositing metal comprising: a substrate; a first lift-off layer deposited on said substrate; a first barrier layer deposited on said first lift-off layer, said first barrier layer having etch properties different from said first lift-off layer; a second lift-off layer deposited on said first barrier layer, said second lift-off layer having etch properties similar to said first lift-off layer; and a second barrier layer deposited on said second lift-off layer, said second barrier layer having etch properties similar to said first barrier layer, whereby undesired metal footing is prevented from being deposited on the substrate by the two barrier layers.
Claim 2
Dependent Claim
105 words
A dual overhang, lift-off structure depositing metal comprising: a substrate; a first lift-off layer deposited on said substrate; a first barrier layer deposited on said first lift-off layer, said first barrier layer having etch properties different from said first lift-off layer; a second lift-off layer deposited on said first barrier layer, said second lift-off layer having etch properties similar to said first lift-off layer; and a second barrier layer deposited on said second lift-off layer, said second barrier layer having etch properties similar to said first barrier layer, whereby undesired metal footing is prevented from being deposited on the substrate by the two barrier layers.
Claim 3
Dependent Claim
24 words
The structure as claimed in claim 1 wherein said first and second lift-off layers are etchable in O 2 or O 2 containing plasma.
Claim 4
Dependent Claim
45 words
The structure as claimed in claim 1 wherein said first and second barrier layers are etchable in a plasma of gas selected from the group consisting of CF 4 , C 2 F 6 or CHF 3 with or without O 2 as an additive.
Claim 5
Dependent Claim
14 words
The structure as claimed in claim 1 wherein said first lift-off layer is polyimide.
Claim 6
Dependent Claim
14 words
The structure as claimed in claim 1 wherein said second lift-off layer is polyimide.
Claim 7
Dependent Claim
16 words
The structure as claimed in claim 1 wherein said first and second lift-off layers are polyimide.
Claim 8
Dependent Claim
14 words
The structure as claimed in claim 1 wherein said first lift-off layer is photoresist.
Claim 9
Dependent Claim
14 words
The structure as claimed in claim 1 wherein said second lift-off layer is photoresist.
Claim 10
Dependent Claim
16 words
The structure as claimed in claim 1 wherein said first and second lift-off layers are photoresist.
Claim 11
Dependent Claim
30 words
The structure as claimed in claim 1 wherein said first barrier layer is selected from the group consisting of HMDS, SiO 2 , Si 3 N 4 and resin glass.
Claim 12
Dependent Claim
30 words
The structure as claimed in claim 1 wherein said second barrier layer is selected from the group consisting of HMDS, SiO 2 , Si 3 N 4 and resin glass.
Claim 13
Dependent Claim
118 words
A dual overhang collimated structure for depositing metal lines on a substrate comprising: a substrate; a first lift-off layer deposited on said substrate, said first layer being etchable in a first etch gas; a first barrier layer deposited on said first lift-off layer, said first barrier layer being etchable in a second etch gas; a second lift-off layer deposited on said first barrier layer, said second lift-off layer having etch properties similar to said first lift-off layer; and a second barrier layer deposited on said second lift-off layer, said second barrier layer having etch properties similar to said first barrier layer, whereby undesired metal footing is prevented from being deposited on the substrate by the two barrier layers.
Claim 14
Dependent Claim
118 words
A dual overhang collimated structure for depositing metal lines on a substrate comprising: a substrate; a first lift-off layer deposited on said substrate, said first layer being etchable in a first etch gas; a first barrier layer deposited on said first lift-off layer, said first barrier layer being etchable in a second etch gas; a second lift-off layer deposited on said first barrier layer, said second lift-off layer having etch properties similar to said first lift-off layer; and a second barrier layer deposited on said second lift-off layer, said second barrier layer having etch properties similar to said first barrier layer, whereby undesired metal footing is prevented from being deposited on the substrate by the two barrier layers.
Claim 15
Dependent Claim
24 words
The structure as claimed in claim 12 wherein said first and second lift-off layers are etchable in O 2 or O 2 containing plasma.
Claim 16
Dependent Claim
46 words
The structure as claimed in claim 12 wherein said first and second barrier layers are etchable in a plasma of gas selected from the group consisting of CF 4 , C 2 F 6 , or CHF 3 with or without O 2 as an additive.
Claim 17
Dependent Claim
14 words
The structure as claimed in claim 12 wherein said first lift-off layer is polyimide.
Claim 18
Dependent Claim
14 words
The structure as claimed in claim 12 wherein said second lift-off layer is polyimide.
Claim 19
Dependent Claim
16 words
The structure as claimed in claim 12 wherein said first and second lift-off layers are polyimide.
Claim 20
Dependent Claim
16 words
The structure as claimed in claim 12 wherein said first and second lift-off layers are photoresist.
Claim 21
Dependent Claim
30 words
The structure as claimed in claim 12 wherein said first barrier layer is selected form the group consisting of HMDS, SiO 2 , Si 3 N 4 and resin glass.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-06-17 | 1994-12-17 | 1995-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-17 | 1998-12-17 | 1999-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-17 | 2002-12-17 | 2003-06-18 | $7700.00 | Window Closed / Lapsed |