Patent EP0437063A2 successfully refreshed from Google Patents.
US3766041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing piezoelectric thin films by cathodic sputtering
Assignee: Panasonic Holdings Corp
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Filing: 1971-09-17
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Granted: 1973-10-16
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Expires: 1991-09-17
Abstract
Abstract An improved method of making piezoelectric thin films comprising zinc oxide having a hexagonal crystalline form by using a cathodic sputtering step capable of controlling the direction of crystallographic orientation in said piezoelectric thin films, characterized in that said cathodic sputtering step comprises cosputtering of copper or aluminum with zinc in an oxidizing atmosphere.
Inventors
- 👤 K Wasa
- 👤 S Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:09
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/0021; C23C14/0036; C23C14/22; C23C14/34; C23C14/3464; H; H01; H01J; H01J37/00; H01J37/32; H01J37/34
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
22 words
A method of making a thin film transducer as claimed in claim 1 in which said solid medium is a quartz rod.
Claim 2
Independent Claim
150 words
A method of making a thin film transducer for use in a high frequency ultrasonic range, comprising making a thin hexagonal zinc oxide piezoelectric film with a c-axis parallel to the film surface containing from .7 to 13 atomic percent aluminum on an amorphous substrate by carrying out a cathodic sputtering step in an oxidizing atmosphere ranging from 10 1 to 10 4 Torr, apparatus having a main cathode of zinc, an anode of conductive material having a high melting point and adapted to have a substrate secured to it and an auxiliary cathode of aluminum positioned between said main cathode and said anode, and supplying a sputtering current to said auxiliary cathode which ranges from 1 to 20 percent of the sputtering current supplied to the main cathode, sandwiching the thin piezoelectric film between metal electrodes, and cementing the resulting assembly to a solid medium which generates shear waves.
Claim 3
Dependent Claim
22 words
A method of making a thin film transducer as claimed in claim 3 in which said solid medium is a quartz rod.
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |