| 摘要 |
PROBLEM TO BE SOLVED: To precisely control an electrostatic capacitance value of a thin-film capacitive device to a desired value, by attaining a specific roughness in the surface of an insulating substrate where at least the thin-film capacitive device is formed. SOLUTION: Two thin-film capacitive devices 3a and 3b are formed on the upper surface of an insulating substrate 1. The thin-film capacitive devices 3a and 3b respectively comprise a thin-film lower electrode layer 5, a dielectric layer 6 on the layer 5, and a thin-film upper electrode layer 7 on the layer 6. The insulating substrate 1 has a flat surface where the surface roughness in regions of the thin-film capacitive devices 3a and 3b is Ra<=0.1μm (Ra: the center-line average roughness). In this structure, in a case where the thin-film lower electrode layer 5 is formed by adopting a thin-film formation technique on the insulating substrate 1, the thin-film lower electrode layer 5 has a uniform thickness all over the layer. Further, the thickness of the dielectric layer 6 and that of the thin-film upper electrode layer 7 formed on the thin-film lower electrode layer 5 are uniform.
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