Patent EP0771070A2 successfully refreshed from Google Patents.
EP0771070A2
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EP
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A film bulk acoustic wave device
Assignee: Mitsubishi Electric Corp
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Filing: 1996-01-22
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Granted: —
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Expires: 2016-01-22
Abstract
Abstract Embodiments of the present invention provide a small and well-characterized bulk acoustic wave device by fabricating a filter having a wide band width or a resonator having a wide oscillation frequency range together with a semiconductor circuit. In embodiments of the present invention, a bulk acoustic wave device comprises a semiconductor substrate having a dielectric substance layer thereon, the dielectric substance layer has a ground conductor layer thereon, the ground conductor layer has a piezoelectric ceramic thin film thereon and the piezoelectric ceramic thin film has a conductive electrode pattern thereon. The thickness of the piezoelectric ceramic thin film is more than ten times the thickness of the ground conductor layer, and the wave number of acoustic waves that propagate in a direction parallel to a surface of the piezoelectric ceramic thin film multiplied by the thickness of the piezoelectric ceramic thin film is less than 2.
Inventors
- 👤 Shusou Wadaka
- 👤 Koichiro Misu
- 👤 Tsutomu Nagatsuka
- 👤 Tomonori Kimura
- 👤 Shunpei Kameyama
- 👤 Chisako Maeda
- 👤 Akira Yamada
- 👤 Toshihisa Honda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 15:58
CPC Classifications
H; H10; H10N; H10N39/00; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/545; H03H3/00; H03H3/007; H03H3/02; H03H9/02; H03H9/05; H03H9/0538; H03H9/0542; H03H9/15; H03H9/17; H03H9/171; H03H9/172; H03H9/173; H03H9/174; H03H9/176; H03H9/56; H03H9/562; H03H9/564
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
69 words
A film bulk acoustic wave device comprising: a semiconductor substrate; a ground conductor layer, having a thickness, mounted on the semiconductor substrate; a piezoelectric ceramic thin film, having a thickness, mounted on the ground conductor layer; and a conductive electrode pattern mounted on the piezoelectric ceramic thin film; wherein the thickness of the piezoelectric ceramic thin film is more than 10 times the thickness of the ground conductor layer.
Claim 2
Dependent Claim
91 words
A film bulk acoustic wave device comprising: a semiconductor substrate; a ground conductor layer mounted on the semiconductor substrate; a piezoelectric ceramic thin film, having a thickness, mounted on the ground conductor layer; and a conductive electrode pattern mounted on the piezoelectric ceramic thin film; wherein the piezoelectric ceramic thin film generates an acoustic wave propagated in a direction parallel to a surface of the piezoelectric ceramic thin film and a wave number of the acoustic waves is less than 2 divided by the thickness of the piezoelectric ceramic thin film.
Claim 3
Dependent Claim
63 words
A film bulk acoustic wave device comprising: a ground conductor layer mounted on the semiconductor substrate; a piezoelectric ceramic thin film mounted on the ground conductor layer; a conductive electrode pattern mounted on the piezoelectric ceramic thin film; and a semiconductor circuit mounted on the semiconductor substrate; wherein the semiconductor circuit is configured by using a part of the piezoelectric ceramic thin film.
Claim 4
Dependent Claim
18 words
The film bulk acoustic wave device of claim 3 wherein the semiconductor circuit is an inductive reactance device.
Claim 5
Dependent Claim
33 words
The film bulk acoustic wave device of claim 4, wherein a characteristic of the inductive reactance device is determined according to shapes of the piezoelectric ceramic thin film and the conductive electrode pattern.
Claim 6
Dependent Claim
28 words
The film bulk acoustic wave device of claim 5, wherein a characteristic of the inductive reactance device is determined according to a shape of the ground conductor layer.
Claim 7
Dependent Claim
70 words
A film bulk acoustic wave device comprising: a semiconductor substrate; a ground conductor layer mounted on the semiconductor substrate; a piezoelectric ceramic thin film mounted on the ground conductor layer; and, a conductive electrode pattern mounted on the piezoelectric ceramic thin film; wherein the piezoelectric ceramic thin film has a piezoelectric section processed by a polarization process and a dielectric section that has not been processed by the polarization process.
Claim 8
Dependent Claim
23 words
The film bulk acoustic wave device of claim 7 wherein the dielectric substance is used as a part of a capacitive reactance device.
Claim 9
Dependent Claim
80 words
A film bulk acoustic wave device comprising: a semiconductor substrate; a ground conductor layer mounted on the semiconductor substrate; a piezoelectric ceramic thin film mounted on the ground conductor layer; a conductive electrode pattern mounted on the piezoelectric ceramic thin film; a semiconductor circuit mounted on the semiconductor substrate; a polarization circuit used for a polarization process of the piezoelectric ceramic thin film; and a protective circuit for protecting the semiconductor circuit from the polarization process by the polarization circuit.
Claim 10
Dependent Claim
38 words
The film bulk acoustic wave device of claim 9, wherein the protective circuit has a capacitive reactance connected in series between the semiconductor circuit and at least one of the ground conductor layer and the conductive electrode pattern.
Claim 11
Dependent Claim
87 words
The film bulk acoustic wave device of claim 9, wherein the semiconductor circuit has a ground potential electrode, and wherein the protective circuit sets one of the conductive electrode pattern and the ground conductor layer to be at a same potential as the ground potential electrode of the semiconductor circuit during a polarization process, disconnects the other of the conductive electrode pattern and the ground conductor layer from the ground potential electrode of the semiconductor circuit and applies a direct current voltage for polarization to the other.
Claim 12
Dependent Claim
118 words
The film bulk acoustic wave device of claim 9, wherein the semiconductor circuit has a ground potential electrode, and wherein the protective circuit sets one of the conductive electrode pattern and the ground conductor to be at a same potential as the ground potential electrode of the semiconductor circuit during a polarization process and applies a direct current voltage for polarization to the other of the conductive electrode pattern and the ground conductor layer through a resistance, and wherein the resistance has a larger resistance value than that of a resistance device which exists in an electric path, from an applied point of the direct current voltage for polarization to the ground potential electrode of the semiconductor circuit.
Claim 13
Dependent Claim
24 words
The film bulk acoustic wave device of claim 9, wherein the polarization circuit is provided for a plurality of film bulk acoustic wave devices.
Claim 14
Dependent Claim
43 words
The film bulk acoustic wave device of claim 13, wherein the polarization circuit has one of a first line to electrically couple a plurality of the ground conductor layers and a second line to electrically couple a plurality of the conductive electrode patterns.
Claim 15
Dependent Claim
23 words
The film bulk acoustic wave device of claim 14, wherein the first and second lines have a characteristic impedance of more than 50Ω.
Claim 16
Dependent Claim
22 words
The film bulk acoustic wave device of claim 14, wherein the first and second lines have a resistance of more than 50Ω.
Claim 17
Dependent Claim
67 words
A film bulk acoustic wave device comprising: a semiconductor substrate; a ground conductor layer mounted on the semiconductor substrate; a piezoelectric ceramic thin film mounted on the ground conductor layer; a conductive electrode pattern mounted on the piezoelectric ceramic thin film; a plurality of reactance devices mounted on the semiconductor substrate; and a means for changing an electrical connection of each of the plurality of reactance devices.
Claim 18
Dependent Claim
28 words
The film bulk acoustic wave device of claim 17, wherein at least one of the plurality of reactance devices includes a part of the piezoelectric ceramic thin film.
Claim 19
Dependent Claim
57 words
A film bulk acoustic wave device comprising: a semiconductor substrate; a ground conductor layer mounted on the semiconductor substrate; a piezoelectric ceramic thin film mounted on the ground conductor layer; a conductive electrode pattern mounted on the piezoelectric ceramic thin film; and an active device circuit that provides a variable capacitive reactance, mounted on the semiconductor substrate.
Claim 20
Dependent Claim
39 words
The film bulk acoustic wave device of claim 19, wherein the active device circuit has an active device, a plurality of resistance devices, and a means for changing an electrical connection of each of the plurality of resistance devices.
Claim 21
Dependent Claim
24 words
The film bulk acoustic wave device of claims 17 and 20, wherein the means for changing the electrical connection connects selected devices in series.
Claim 22
Dependent Claim
24 words
The film bulk acoustic wave device of claims 17 and 20, wherein the means for changing the electrical connection connects selected devices in parallel.
Claim 23
Dependent Claim
25 words
The film bulk acoustic wave device of claims 17 and 20, wherein the means for changing the electrical connection changes the electrical connection using wire-bonding.
Claim 24
Dependent Claim
31 words
The film bulk acoustic wave device of claims 17 and 20, wherein the means for changing the electrical connection changes the electrical connection by using a mask for producing an electrode.
Claim 25
Dependent Claim
28 words
The film bulk acoustic wave device of claims 17 and 20, wherein the means for changing the electrical connection changes the electrical connection by cutting an electrode pattern.
Claim 26
Dependent Claim
32 words
The film bulk acoustic wave device of claim 1, 2, 3, 7, 8, 17, and 19, wherein the piezoelectric ceramic thin film is comprised of one of lead titanate and lead titanate-zirconate.
Claim 27
Dependent Claim
22 words
The film bulk acoustic wave device of claim 26, wherein the semiconductor substrate is comprised of one of silicon and gallium arsenide.
Claim 28
Dependent Claim
22 words
The film bulk acoustic wave device of claim 27, wherein the ground conductor layer uses at least one of platinum and gold.
Claim 29
Dependent Claim
20 words
The film bulk acoustic wave device of claim 28, wherein the ground conductor layer uses one of titanium and tungsten.
Claim 30
Dependent Claim
27 words
The film bulk acoustic wave device of claim 29, wherein the conductive electrode pattern uses one of a metal, a conductive semiconductor layer and a conductive material.
Claim 31
Dependent Claim
24 words
The film bulk acoustic wave device of claim 26, further comprising a dielectric substance layer between the semiconductor substrate and the ground conductor layer.
Claim 32
Dependent Claim
23 words
The piezoelectric thin film of claim 31, wherein the piezoelectric ceramic thin film is mounted on a part of the dielectric substance layer.
Claim 33
Dependent Claim
27 words
The film bulk acoustic wave device of claim 31, wherein the dielectric substance layer is mainly composed of one of silicon oxide, silicon nitride and tantalum oxide.
Claim 34
Dependent Claim
38 words
The film bulk acoustic wave device of claim 26, further comprising at least one of a semiconductor circuit, an active circuit device and a passive circuit device on the semiconductor substrate, so as to configure an electronic system.
Claim 35
Dependent Claim
53 words
The film bulk acoustic wave device of claims 2, 3, 7, 8, 17 and 19, wherein the ground conductor layer has a thickness and the piezoelectric ceramic thin film has a thickness and the thickness of the piezoelectric ceramic thin film is more than 10 times the thickness of the ground conductor layer.
Claim 36
Dependent Claim
69 words
The film bulk acoustic wave device of claims 1, 3, 7, 8, 17, and 19, wherein the piezoelectric ceramic thin film has a thickness and wherein the piezoelectric ceramic thin film generates an acoustic wave to propagate in a direction parallel to a surface of the piezoelectric ceramic thin film and a number of acoustic waves is less than 2 divided by the thickness of the piezoelectric thin film.
Claim 37
Independent Claim
57 words
A method of manufacturing a film bulk acoustic wave device comprising the steps of: (a) forming a ground conductor layer on a semiconductor substrate; (b) forming a piezoelectric ceramic thin film of one of lead titanate and lead titanate-zirconate on the ground conductor layer; and (c) forming a conductive electrode pattern on the piezoelectric ceramic thin film.
Claim 38
Dependent Claim
41 words
The method of manufacturing the thin film piezoelectric of claim 37, further comprising the step of forming a dielectric substance layer by layering one of silicon oxide, silicon nitride, and tantalum oxide between the semiconductor substrate and the ground conductor layer.
Claim 39
Dependent Claim
71 words
The method of manufacturing the film bulk acoustic wave device of claim 37, wherein the step of forming the ground conductor layer includes a step of setting a thickness of the ground conductor layer, and the step of forming the piezoelectric ceramic thin film includes a step of setting the thickness of the piezoelectric ceramic thin film to be more than ten times of the thickness of the ground conductor layer.
Claim 40
Dependent Claim
70 words
The method of manufacturing the film bulk acoustic wave device of claim 37, wherein the step of forming the piezoelectric ceramic thin film includes a step of forming the piezoelectric ceramic thin film wherein a product of a thickness of the piezoelectric ceramic thin film and a number of acoustic waves to propagate in a direction parallel to a surface of the piezoelectric ceramic thin film is less than 2.
Claim 41
Dependent Claim
32 words
The method of manufacturing the film bulk acoustic wave device of claim 37, further comprising a step of forming a semiconductor circuit by using a part of the piezoelectric ceramics thin film.
Claim 42
Dependent Claim
27 words
The method of manufacturing the film bulk acoustic wave device of claim 37, further comprising a step of polarizing only part of the piezoelectric ceramic thin film.
Claim 43
Dependent Claim
47 words
The method of manufacturing the film bulk acoustic wave device of claim 37, further comprising a step of forming a semiconductor circuit on the semiconductor substrate, a step of polarizing the piezoelectric ceramic thin film, and a step of protecting the semiconductor circuit during the polarization process.
Claim 44
Dependent Claim
56 words
The method of manufacturing the bulk acoustic wave device of claim 37, further comprising a step of forming a plurality of devices to adjust a characteristic of the film bulk acoustic wave device, and a step of adjusting the characteristic of the film bulk acoustic wave device by selectively connecting devices of the plurality of devices.
References Cited (Backward Citations)
No citation records indexed.
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