Patent US5364743A successfully refreshed from Google Patents.
US5364743A
Expired / Lapsed
US
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Process for fabrication of bubble jet using positive resist image reversal for lift off of passivation layer
Assignee: Xerox Corp
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Filing: 1992-12-31
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Granted: 1994-11-15
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Expires: 2012-12-31
Abstract
Abstract In bubble jet heater dies, a photolithographic process is disclosed to form patterned photoresist structures having re-entrant angles to facilitate an improved lift-off structure for anti-cavitation layer deposition. A substrate is coated with a photoresist which includes 0.5% to 1.0% Monazoline C. When exposed to Ultra-Violet light and developed, apertures in the photoresist have inverted side walls. Anti-cavitation material, such as tantalum, is then sputtered onto the substrate and the photoresist to form patterned metal. structures. The lift-off of the patterned photoresist is easily performed leaving behind the patterned metal structures. The use of this lift-off deposition method prevents stress-cracking in the anti-cavitation layer seen in deposition and etch methods.
Inventors
- 👤 James F. O'Neill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:50
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2022; G03F7/004; G03F7/022; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49401
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
177 words
A method of forming patterned anti-cavitation damage layers in isolated regions in a thermal ink jet print head in order to avoid stress cracking, said thermal ink jet print head comprising heaters, said method comprising: coating a heater on a substrate of said thermal ink jet print head with modified photoresist to form a photoresist layer; exposing said photoresist layer, said heater and said substrate with electromagnetic radiation through a mask, said mask comprising areas transparent and opaque to said electromagnetic radiation; baking said substrate, said heater and photoresist layer for a period of time; blanket exposing said substrate, said heater and photoresist layer for a period of time; developing said photoresist layer sufficiently to form patterned structures in said photoresist layer, said patterned structures having inverted side walls; depositing metal onto said heater and photoresist layer sufficiently to form a patterned anti-cavitation damage layer in isolated regions of said substrate such that stress cracking in said anti-cavitation damage layer is avoided; and removing said photoresist layer, such that said patterned anti-cavitation layer remains on said heater.
Claim 2
Independent Claim
177 words
A method of forming patterned anti-cavitation damage layers in isolated regions in a thermal ink jet print head in order to avoid stress cracking, said thermal ink jet print head comprising heaters, said method comprising: coating a heater on a substrate of said thermal ink jet print head with modified photoresist to form a photoresist layer; exposing said photoresist layer, said heater and said substrate with electromagnetic radiation through a mask, said mask comprising areas transparent and opaque to said electromagnetic radiation; baking said substrate, said heater and photoresist layer for a period of time; blanket exposing said substrate, said heater and photoresist layer for a period of time; developing said photoresist layer sufficiently to form patterned structures in said photoresist layer, said patterned structures having inverted side walls; depositing metal onto said heater and photoresist layer sufficiently to form a patterned anti-cavitation damage layer in isolated regions of said substrate such that stress cracking in said anti-cavitation damage layer is avoided; and removing said photoresist layer, such that said patterned anti-cavitation layer remains on said heater.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein in said coating step, said photoresist includes 0.5% to 1.0% of a 1-hydroxyethyl-2 alkylimidazoline.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein in said depositing step, said metal is tantalum.
Claim 5
Dependent Claim
18 words
The method of claim 2 wherein in said baking step, said period of time is approximately ten minutes.
Claim 6
Dependent Claim
27 words
The method of claim 2 wherein in said baking step, said substrate and patterned photoresist layer are heated to a temperature between 95° C. and 100° C.
Claim 7
Dependent Claim
16 words
The method of claim 2 wherein in said exposing step, said electromagnetic radiation is Ultra-Violet light.
Claim 8
Independent Claim
244 words
A method of forming patterned anti-cavitation damage layers in isolated regions in a thermal ink jet print head in order to avoid stress cracking by physical forces that act upon a blanket coated layer, said thermal ink jet print head comprising heaters, said method comprising: providing a substrate of a thermal ink jet print head; said substrate having a plurality of heaters being equally spaced apart and having a density of between 150 and 1200 heater per inch; coating said plurality of heaters on said substrate of said thermal ink jet print head with modified photoresist to form a photoresist layer; exposing said photoresist layer, said heaters and said substrate with electromagnetic radiation through a mask, said mask comprising areas transparent and opaque to said electromagnetic radiation; baking said substrate, said heaters and photoresist layer for a period of time; blanket exposing said substrate, said heaters and photoresist layer for a period of time; developing said photoresist layer sufficiently to form patterned structures in said photoresist layer, said patterned structures having inverted side walls; depositing metal onto said heater and photoresist layer sufficiently to form a patterned anti-cavitation damage layer in isolated regions of said substrate over each of said heaters such that stress cracking in said anti-cavitation damage layer due to blanket coating said anti-cavitation damage layer over a relatively large area of said substrate is avoided; and removing said photoresist layer, such that said each patterned anti-cavitation layer remains on said heater.
Claim 9
Independent Claim
244 words
A method of forming patterned anti-cavitation damage layers in isolated regions in a thermal ink jet print head in order to avoid stress cracking by physical forces that act upon a blanket coated layer, said thermal ink jet print head comprising heaters, said method comprising: providing a substrate of a thermal ink jet print head; said substrate having a plurality of heaters being equally spaced apart and having a density of between 150 and 1200 heater per inch; coating said plurality of heaters on said substrate of said thermal ink jet print head with modified photoresist to form a photoresist layer; exposing said photoresist layer, said heaters and said substrate with electromagnetic radiation through a mask, said mask comprising areas transparent and opaque to said electromagnetic radiation; baking said substrate, said heaters and photoresist layer for a period of time; blanket exposing said substrate, said heaters and photoresist layer for a period of time; developing said photoresist layer sufficiently to form patterned structures in said photoresist layer, said patterned structures having inverted side walls; depositing metal onto said heater and photoresist layer sufficiently to form a patterned anti-cavitation damage layer in isolated regions of said substrate over each of said heaters such that stress cracking in said anti-cavitation damage layer due to blanket coating said anti-cavitation damage layer over a relatively large area of said substrate is avoided; and removing said photoresist layer, such that said each patterned anti-cavitation layer remains on said heater.
Claim 10
Dependent Claim
35 words
The method of claim 7 wherein said heaters are placed on said substrate with a density of 300 heaters per inch, such that each anti-cavitation damage layer as a width between 61 and 81 μm.
Claim 11
Dependent Claim
16 words
The method of claim 8 wherein each anti-cavitation damage layer has a length of 144 μm.
Claim 12
Dependent Claim
30 words
The method of claim 9 wherein said providing step includes providing a substrate wherein each of said heaters are substantially identical in configuration, rectangularly shaped, and arranged in parallel fashion.
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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) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |