US4642508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric resonating device
Assignee: Toshiba Corp
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Filing: 1985-03-08
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Granted: 1987-02-10
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Expires: 2005-03-08
Abstract
Abstract The present invention provides a piezoelectric thin-film resonator comprising a non-piezoelectric film layer formed on a substrate, a lower electrode, a piezoelectric film layer and an upper electrode. An air-gap layer is formed between the non-piezoelectric film and the substrate to facilitate vibration of the piezoelectric film layer at the resonate frequency. The resulting resonating device is mechanically strong while at the same time being capable of operating at high frequency.
Inventors
- 👤 Hitoshi Suzuki
- 👤 Hiroaki Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:22
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/15; H03H9/17; H03H9/171; H03H9/172; H03H9/173; H03H3/00; H03H3/007; H03H3/02; H03H3/04; H03H9/02; H03H9/02007; H03H9/02086; H03H9/02102; H03H9/02133; H03H9/46; H03H9/54; H03H9/56; H03H9/564; H10; H10N; H10N30/00; H10N30/01; H10N30/07; H10N30/074; H10N30/076; H10N30/08; H10N30/081; H10N30/082
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
79 words
A piezoelectric resonating device comprising: a substrate having a substantially flat surface; a non-piezoelectric film layer formed on said flat surface to create an air-gap between a portion of said non-piezoelectric film layer and said flat surface; a first electrode formed on said non-piezoelectric film and extending along said air-gap; a piezoelectric film layer formed on said non-piezoelectric film layer and said first electrode; and a second electrode formed on said piezoelectric film layer and extending along said air-gap.
Claim 2
Dependent Claim
79 words
A piezoelectric resonating device comprising: a substrate having a substantially flat surface; a non-piezoelectric film layer formed on said flat surface to create an air-gap between a portion of said non-piezoelectric film layer and said flat surface; a first electrode formed on said non-piezoelectric film and extending along said air-gap; a piezoelectric film layer formed on said non-piezoelectric film layer and said first electrode; and a second electrode formed on said piezoelectric film layer and extending along said air-gap.
Claim 3
Dependent Claim
60 words
A piezoelectric resonating device according to claim 1 wherein said air-gap is formed by the following steps: forming a dummy film layer on said flat surface; forming said non-piezoelectric film layer on said flat surface and said dummy film layer; and removing said dummy film layer by soaking said flat surface in a solution which dissolves said dummy film layer.
Claim 4
Dependent Claim
17 words
A piezoelectric resonating device according to claim 1 wherein said non-piezoelectric film layer comprises SiO 2 film.
Claim 5
Dependent Claim
19 words
A piezoelectric resonating device according to claim 1 wherein said non-piezoelectric film layer comprises Si 3 N 4 film.
Claim 6
Dependent Claim
37 words
A piezoelectric resonating device according to claim 1 wherein said non-piezoelectric film layer comprises Si 3 N 4 film formed on said flat surface and a SiO 2 film formed on said Si 3 N 4 film.
Claim 7
Dependent Claim
16 words
A piezoelectric resonating device according to claim 1 wherein said first electrode has a L-shaped pattern.
Claim 8
Dependent Claim
16 words
A piezoelectroc resonating device according to claim 1 wherein said second electrode has an L-shaped pattern.
Claim 9
Dependent Claim
18 words
A piezoelectric resonating device according to claim 6 wherein said second electrode includes a pair of independent electrodes.
Claim 10
Dependent Claim
16 words
A piezoelectric resonating device according to claim 1 wherein said piezoelectric film comprises a ZnO film.
Claim 11
Dependent Claim
88 words
A piezoelectric resonating device comprising: a substrate having a substantially flat surface; a non-piezoelectric film layer formed on said flat surface to create an air-gap between said non-piezoelectric film layer and said flat surface; a lower electrode formed on said non-piezoelectric film layer; a piezoelectric film layer formed on said non-piezoelectric film layer and said lower electrode; an upper electrode formed on said piezoelectric film layer so as to interface with said lower electrode; and a dielectric film layer formed on said piezoelectric film and said upper electrode.
Claim 12
Dependent Claim
88 words
A piezoelectric resonating device comprising: a substrate having a substantially flat surface; a non-piezoelectric film layer formed on said flat surface to create an air-gap between said non-piezoelectric film layer and said flat surface; a lower electrode formed on said non-piezoelectric film layer; a piezoelectric film layer formed on said non-piezoelectric film layer and said lower electrode; an upper electrode formed on said piezoelectric film layer so as to interface with said lower electrode; and a dielectric film layer formed on said piezoelectric film and said upper electrode.
Claim 13
Dependent Claim
70 words
A piezoelectric resonating device according to claim 10 wherein said air-gap is formed by the following steps: forming a dummy film layer of said flat surface corresponding to said air-gap; forming said non-piezoelectric film layer, said lower electrode, said piezoelectric film layer, said upper electrode and said dielectric film successively; and soaking said flat surface in a solution which dissolves said dummy film layer so as to form said air-gap.
Claim 14
Dependent Claim
20 words
A piezoelectric resonating device according to claim 10 wherein said dielectric film layer is comprised of a SiO 2 film.
Claim 15
Dependent Claim
19 words
A piezoelectric resonating device according to claim 12 wherein said piezoelectric film layer is comprised of a ZnO film.
Claim 16
Dependent Claim
20 words
A piezoelectric resonating device according to claim 13 wherein said non-piezoelectric film layer is comprised of an SiO 2 film.
Claim 17
Dependent Claim
39 words
A piezoelectric resonating device according to claim 13 wherein said non-piezoelectric film layer is comprised of: a Si 3 N 4 film formed on said substrate; and a SiO 2 film formed on said Si 3 N 4 film.
Claim 18
Dependent Claim
51 words
A piezoelectric resonating device comprising: a substrate having a substantially flat surface; a metal film layer formed on said flat surface to create an air-gap between said flat surface and said metal film; a piezoelectric film formed on said metal film; and an upper electrode formed on said piezoelectric film layer.
Claim 19
Dependent Claim
51 words
A piezoelectric resonating device comprising: a substrate having a substantially flat surface; a metal film layer formed on said flat surface to create an air-gap between said flat surface and said metal film; a piezoelectric film formed on said metal film; and an upper electrode formed on said piezoelectric film layer.
Claim 20
Dependent Claim
27 words
A piezoelectric resonating device according to claim 15 wherein the device further comprises a dielectric film layer formed on said piezoelectric film layer and said upper electrode.
References Cited (Backward Citations)
US3486046A
Cited
JPS5829211A
Cited
JPS5831609A
Cited
US4456850A
Cited
JPS58137318A
Cited
JPS58175314A
Cited
US4531267A
Cited
US4502932A
Cited
US4517486A
Cited
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