摘要 |
A surface acoustic wave device used as a branching filter and the like in, for example, a mobile communications field to handle high frequencies of about several GHz is manufacturable by forming a metal film on a wafer-like piezoelectric substrate and selectively removing the metal film to form comb-teeth-shaped metal electrodes. The metal film is partly formed in two or more film-forming modes involving different in-wafer-plane film-forming-velocity distributions, and the remaining part thereof is formed in a fixed film-forming mode. An in-wafer-plane film-thickness distribution of a part of the metal film is precisely controllable. Forming the remaining part of the metal film precisely controls the final thickness of the metal film. <IMAGE>
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