| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezo-resonator having high yield rate, in which stress that a thin film has is made extremely small and which is superior in resonance characteristics. <P>SOLUTION: The resonator includes a substrate 2, an insulating film 4 formed above the substrate 2, an oscillation section 8 having a structure that top and bottom surfaces of a thin film section which has at least one or more layers of piezoelectric thin film are sandwiched by at least one pair of upper electrode 7 and a lower electrode 5 by facing with each other in a thickness direction, and the roughness arithmetic average (Ra) of the lower electrode is 2.5nm or less. Preferably, the surface of the insulating film 4 has the roughness arithmetic average (Ra) of 1.0nm or less, and the stress of the insulating film 4 is set to 250MPa or less on compressive stress and 400MPa on tensile stress. <P>COPYRIGHT: (C)2004,JPO |
