Frequency Adjustment of Surface Acoustic Wave Devices through Crystal Rotation

摘要

This document discloses a method for varying the center frequency of a surface acoustic wave device using a single common photomask. At least two piezoelectric substrates are prepared for photolithographic transference of a transducer pattern onto the substrates. Each of the piezoelectric substrates has a predominant wave propagation axis. In a first iteration, the photomask is utilized to transfer the transducer pattern contained therein onto a first of the piezoelectric substrates at a predetermined orientation angle with respect to the wave propagation axis to thereby form a surface acoustic wave device. Subsequently the same photomask is used in a similar photolithographic process to create one or more additional surface acoustic wave devices having different center frequencies of operation. The change in frequency of operation is brought about by relative rotation of the photomask in the photolithographic process such that the photomask is at a different orientation angle with respect to the wave propagation axis of each piezoelectric substrate. The single photomask is thus used to create at least two surface acoustic wave devices having different center frequencies of operation. (Author)