Wave transmission lines and networks – Coupling networks – Electromechanical filter
Reexamination Certificate
2006-10-31
2006-10-31
Takaoka, Dean (Department: 2817)
Wave transmission lines and networks
Coupling networks
Electromechanical filter
C333S191000, C310S324000
Reexamination Certificate
active
07129806
ABSTRACT:
A thin film bulk acoustic wave resonator and method of producing same are provided. The thin film bulk acoustic wave resonator has a superior resonance characteristic (e.g., high-orientation and densification of a piezoelectric film), wherein the thin film bulk acoustic wave resonator that a local stress to a piezoelectric film is relaxed and improvement of productivity due to a stable structure without causing a crack of the piezoelectric film and high yield and a corresponding cost-reduction are realized, and the production method of the same, such as in an air bridge type thin film bulk acoustic wave resonator. In a region including a substrate, a support layer formed convexly on the substrate and a gap upper that the support layer, laminate of a bottom electrode, a piezoelectric film and a top electrode is formed, where the laminate is formed on the substrate and the support layer. The gap is formed between the support layer and the bottom electrode so that at least a portion of it is located upper than a surface of the support layer, and composes (makes up) a resonance region. For example, the support layer has a height of 20% or more of the maximum height from the support layer surface to the top of the gap.
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Bell Boyd & Lloyd LLC
Takaoka Dean
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