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US4205117A
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Piezoelectric crystalline film of zinc oxide and method for making same
Assignee: Murata Manufacturing Co Ltd
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Filing: 1978-09-07
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Granted: 1980-05-27
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Expires: 1998-09-07
Abstract
Abstract Piezoelectric crystalline film on a substrate, which is a crystalline zinc oxide film with a c-axis substantially perpendicular to the substrate surface, the crystalline zinc oxide film containing, as an additive element, phosphorus. The piezoelectric crystalline films have high resistivity and a smooth surface, and make it possible to produce piezoelectric transducers with good conversion efficiency. Such films are made by sputtering zinc oxide and phosphorus onto a substrate from a film material source consisting essentially of a ceramic of zinc oxide containing phosphorus.
Inventors
- 👤 Hiroshi Nishiyama
- 👤 Toshio Ogawa
- 👤 Tasuku Mashio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:16
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/85; H10N30/853; H10N30/01; H10N30/07; H10N30/074; H10N30/076; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31826; Y10T428/31855; Y10T428/31931
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
45 words
A piezoelectric crystalline film disposed on a substrate, said film consisting essentially of a crystalline zinc oxide film with a hexagonal crystal structure and a c-axis substantially perpendicular to the substrate surface, said crystalline zinc oxide film containing 0.01 to 20.0 atomic percent of phosphorus.
Claim 2
Dependent Claim
45 words
A piezoelectric crystalline film disposed on a substrate, said film consisting essentially of a crystalline zinc oxide film with a hexagonal crystal structure and a c-axis substantially perpendicular to the substrate surface, said crystalline zinc oxide film containing 0.01 to 20.0 atomic percent of phosphorus.
Claim 3
Dependent Claim
29 words
The piezoelectric crystalline film of claim 1 wherein said substrate is made of a material selected from the group consisting of metal, glass, ceramics, single crystals, resins and rubber.
Claim 4
Independent Claim
143 words
A method for making piezoelectric crystalline films comprising simultaneously sputtering zinc oxide and phosphorus from a film material source onto a substrate to form a crystalline zinc oxide film with a hexagonal crystal structure and a c-axis substantially perpendicular to the substrate surface containing 0.01 to 20.0 atomic percent of phosphorus, wherein said sputtering is effected by radio-frequency sputtering in an atmosphere of argon, or oxygen, or a mixture of argon and oxygen under a pressure of 1×10 -1 to 1×10 -4 Torr, and wherein said film material source consists essentially of a ceramic of zinc oxide containing 0.01 to 20.0 atomic percent of phosphorus, said substrate being positioned on an anode placed in parallel with a cathode on which said film material source is positioned, said film material source being supplied with an electric power of 2 to 8 W/cm 2 .
Claim 5
Independent Claim
143 words
A method for making piezoelectric crystalline films comprising simultaneously sputtering zinc oxide and phosphorus from a film material source onto a substrate to form a crystalline zinc oxide film with a hexagonal crystal structure and a c-axis substantially perpendicular to the substrate surface containing 0.01 to 20.0 atomic percent of phosphorus, wherein said sputtering is effected by radio-frequency sputtering in an atmosphere of argon, or oxygen, or a mixture of argon and oxygen under a pressure of 1×10 -1 to 1×10 -4 Torr, and wherein said film material source consists essentially of a ceramic of zinc oxide containing 0.01 to 20.0 atomic percent of phosphorus, said substrate being positioned on an anode placed in parallel with a cathode on which said film material source is positioned, said film material source being supplied with an electric power of 2 to 8 W/cm 2 .
Claim 6
Dependent Claim
30 words
The method for making piezoelectric crystalline films according to claim 3 wherein the substrate is maintained at a temperature in the range of 20° C. to 600° C. during sputtering.
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) | 1983-05-27 | 1983-11-26 | 1984-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-27 | 1987-11-26 | 1988-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-27 | 1991-11-26 | 1992-05-27 | $7700.00 | Window Closed / Lapsed |