US4612274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron beam/optical hybrid lithographic resist process in acoustic wave devices
Assignee: CTS Corp
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Filing: 1985-11-18
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Granted: 1986-09-16
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Expires: 2005-11-18
Abstract
Abstract A method is disclosed for using a combination of electron beam and photo lithography in making a acoustic wave device. The process is preformed by first using a positive photoresist and electron beam writing to designate the fine lines required in acoustic wave devices. Next, a second photoresist and optical lithography are used to delineate the pad areas.
Inventors
- 👤 Frederick Y. Cho
- 👤 John R. Joseph
- 👤 Philip A. Seese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:55
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2022; Y; Y10; Y10S; Y10S430/00; Y10S430/143
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
246 words
A hybrid process of electron beam and optical lithography for making acoustic wave devices comprising the steps of: providing a substrate; placing a layer of Aluminum on said substrate; placing a layer of positive photoresist on said layer of Aluminum; exposing a portion of said positive photoresist with an electron beam delineating a fine line of one micron or less; developing said positive photoresist removing said exposed portion of said positive photoresist causing a first portion of said Aluminum layer to be exposed; placing a layer of Titanium over the surface of a remaining portion of said positive photoresist and the exposed surface of said Aluminum; removing said remaining portion of said positive photoresist causing the Titanium disposed on the surface of said positive photoresist to be removed and exposing a second portion of said Aluminum; placing a layer of a second photoresist over said second portion of said Aluminum and over a remaining portion of said Titanium; masking a portion of said second photoresist designating a pad area; exposing said second photoresist using an optical lithographic technique; developing said second photoresist causing a remaining portion of said second photoresist to be removed; etching said Aluminum causing a portion of said Aluminum to be removed from said acoustic wave device, leaving a portion of said Aluminum disposed below said portion of said second photoresist and a portion of said Aluminum disposed below said remaining portion of said Titanium; and removing said portion of said second photoresist.
Claim 2
Dependent Claim
246 words
A hybrid process of electron beam and optical lithography for making acoustic wave devices comprising the steps of: providing a substrate; placing a layer of Aluminum on said substrate; placing a layer of positive photoresist on said layer of Aluminum; exposing a portion of said positive photoresist with an electron beam delineating a fine line of one micron or less; developing said positive photoresist removing said exposed portion of said positive photoresist causing a first portion of said Aluminum layer to be exposed; placing a layer of Titanium over the surface of a remaining portion of said positive photoresist and the exposed surface of said Aluminum; removing said remaining portion of said positive photoresist causing the Titanium disposed on the surface of said positive photoresist to be removed and exposing a second portion of said Aluminum; placing a layer of a second photoresist over said second portion of said Aluminum and over a remaining portion of said Titanium; masking a portion of said second photoresist designating a pad area; exposing said second photoresist using an optical lithographic technique; developing said second photoresist causing a remaining portion of said second photoresist to be removed; etching said Aluminum causing a portion of said Aluminum to be removed from said acoustic wave device, leaving a portion of said Aluminum disposed below said portion of said second photoresist and a portion of said Aluminum disposed below said remaining portion of said Titanium; and removing said portion of said second photoresist.
Claim 3
Dependent Claim
13 words
The hybrid process of claim 1 wherein said positive photoresist is polymethylmethacrylate (PMMA).
Claim 4
Dependent Claim
253 words
A hybrid process of electron beam and optical lithography for making acoustic wave devices comprising the steps of: providing a substrate; placing a layer of Aluminum on said substrate; placing a layer of positive photoresist on said layer of Aluminum; exposing a portion of said positive photoresist with an electron beam delineating a fine line of one micron or less; developing said positive photoresist removing said exposed portion of said positive photoresist causing a first portion of said Aluminum layer to be exposed; placing a layer of metal over the surface of a remaining portion of said positive photoresist and the exposed surface of said Aluminum; removing said remaining portion of said positive photoresist causing the metal disposed on the surface of said positive photoresist to be removed and exposing a second portion of said Aluminum; placing a layer of a second photoresist over said second portion of said Aluminum and over a remaining portion of said metal; masking a portion of said second photoresist designating a pad area; exposing said second photoresist using an optical lithographic technique; developing said second photoresist causing a remaining portion of said second photoresist to be removed; etching said Aluminum causing a portion of said Aluminum to be removed from said acoustic wave device, leaving a portion of said Aluminum disposed below said portion of said second photoresist and a portion of said Aluminum disposed below said remaining portion of said metal; removing said portion of said second photoresist; and removing said remaining portion of said metal.
Claim 5
Dependent Claim
253 words
A hybrid process of electron beam and optical lithography for making acoustic wave devices comprising the steps of: providing a substrate; placing a layer of Aluminum on said substrate; placing a layer of positive photoresist on said layer of Aluminum; exposing a portion of said positive photoresist with an electron beam delineating a fine line of one micron or less; developing said positive photoresist removing said exposed portion of said positive photoresist causing a first portion of said Aluminum layer to be exposed; placing a layer of metal over the surface of a remaining portion of said positive photoresist and the exposed surface of said Aluminum; removing said remaining portion of said positive photoresist causing the metal disposed on the surface of said positive photoresist to be removed and exposing a second portion of said Aluminum; placing a layer of a second photoresist over said second portion of said Aluminum and over a remaining portion of said metal; masking a portion of said second photoresist designating a pad area; exposing said second photoresist using an optical lithographic technique; developing said second photoresist causing a remaining portion of said second photoresist to be removed; etching said Aluminum causing a portion of said Aluminum to be removed from said acoustic wave device, leaving a portion of said Aluminum disposed below said portion of said second photoresist and a portion of said Aluminum disposed below said remaining portion of said metal; removing said portion of said second photoresist; and removing said remaining portion of said metal.
Claim 6
Dependent Claim
11 words
The hybrid process of claim 3 wherein said metal is Titanium.
Claim 7
Dependent Claim
13 words
The hybrid process of claim 3 wherein said positive photoresist is polymethylmethacrylate (PMMA).
References Cited (Backward Citations)
JPS54162460A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |