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Title:
VARIABLE CAPACITANCE ELEMENT AND ITS MANUFACTURE
Document Type and Number:
Japanese Patent JP3599528
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To provide a variable capacitance element the capacitance of which can be changed largely under a low voltage by successively providing a lower electrode, a thin dielectric film, and an upper electrode on a substrate, with the thin dielectric film being composed of multiple layers.
SOLUTION: After a lower electrode resist pattern, a Ta lower electrode bonding layer 2, and a Pt lower electrode layer 3 are successively formed on a ceramic substrate 1, a lower electrode pattern is formed by lifting off the lower electrode resist pattern. Then, a sol-like precursor solution composed of the metallic alkoxide of SrTiO3 is spin-coated on the Pt lower electrode layer 3 (process 1) and a dried gel thin film is formed by heat-treating the solution (process 2). After the dried gel thin film is formed, the organic matters contained in the thin film are thermally decomposed by heat-treating the thin film in the air (process). After the processes 1 to 3 are repeated three times, a dielectric multilayered thin film 4 of SrTiO3 is formed by crystallizing the multilayered film. Finally, an upper electrode pattern composed of a Ta upper electrode bonding layer 6 and a Pt upper electrode layer 7 is formed.


Inventors:
Ryusuke Kita
Yoshiyuki Masuda
Yoshiyuki Matsu
Noboru Otani
Application Number:
JP15262497A
Publication Date:
December 08, 2004
Filing Date:
June 10, 1997
Export Citation:
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Assignee:
Sharp Corporation
International Classes:
H01G7/06; (IPC1-7): H01G7/06
Domestic Patent References:
JP8306865A
JP8157215A
JP8236705A
JP8213560A
JP4367211A
JP7502149A
Attorney, Agent or Firm:
Shintaro Nogawa