Method of making surface wave devices

摘要

A surface wave device is made by forming conductors on a surface of a piezoelectric material in a conductor pattern defined by exposing photoresist via a reticle. The conductor pattern is provided on the reticle in two parts each defining a set of substantially alternate fingers of the pattern, and the photoresist is exposed by two overlaid exposures each via a respective one of the two parts of the conductor pattern. Exposed photoresist can optionally be developed between the two exposures, and conductors can optionally be formed on the surface between the two exposures. The method reduces diffraction limits, permitting manufacture of surface wave devices with sub-micron linewidths for filtering at increased frequencies.