Tunable thin film capacitor
AssigneeKYOCERA Corporation
InventorsYukihiko Yashima, Kazuhiro Kusabe, Tsuneo Mishima, Tetsuya Kishino
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Abstract
It is an object of the invention to provide a variable capacitor constituted such that, even when an external control voltage is applied, a stable dielectric constant of the dielectric layer can be obtained. A variable capacitor constituted such that a dielectric layer whose dielectric constant is changed by the application of an external voltage is held between an upper electrode layer and a lower electrode layer, wherein a plurality of capacitance-producing regions a, b are connected to each other.
Claims12
A tunable thin film capacitor comprising
- a support substrate,
- a lower electrode layer provided on the support substrate,
- a thin film dielectric layer which is provided on the lower electrode layer and whose dielectric constant is changed by application of a control voltage, and
- an upper electrode layer provided on the thin film dielectric layer,
- wherein the thin film dielectric layer is held between the lower electrode layer and the upper electrode layer so an to form a plurality of capacitance-producing regions;
- and the respective capacitance-producing regions are electrically connected to each other,
- wherein the thin film dielectric layer comprises perovskite-type oxide crystal grains containing at least Ba, Sr and Ti, and the crystal grains are orientated in a plane (111).
A tunable thin film capacitor comprising:
- a support substrate,
- a lower electrode layer provided on the support substrate,
- a thin film dielectric layer which is provided on the lower electrode layer end whose dielectric constant is changed by application of a control voltage, and
- an upper electrode layer provided on the thin film dielectric layer,
- wherein the thin film dielectric layer is held between the lower electrode layer and the upper electrode layer so as to form a plurality of capacitance-producing regions, and the respective capacitance-producing regions are electrically connected to each other,
- wherein the thin film dielectric layer comprises perovskite-type crystal grains containing at least Ba, Sr and Ti, and a composition thereof is represented as (BaSr) TixO3, wherein x in the composition is in a range of 0.7 to 0.9.
A tunable thin film capacitor comprising:
- a support substrate,
- a lower electrode layer provided on the support substrate,
- a thin film dielectric layer which in provided on the lower electrode layer and whose dielectric constant is changed by application of a control voltage, and
- an upper electrode layer provided on the thin film dielectric layer,
- wherein the thin film dielectric layer is held between the lower electrode layer and the upper electrode layer so as to form a plurality of capacitance-producing regions, and the respective capacitance-producing regions are electrically connected to each other,
- wherein the thin film dielectric layer comprises perovskite-type oxide crystal grains containing at least Ba, Sr and Ti, and the crystal grains are orientated at random.
Dependencies are inferred from the claim text.