Patent ID: 8186030

Claim:
A method for manufacturing an elastic wave device, comprising: forming comb-shaped electrodes for exciting elastic waves on a piezoelectric substrate; forming a dielectric layer having a thickness greater than that of the comb-shaped electrodes so as to cover the comb-shaped electrodes, forming an etch back layer so as to cover the dielectric layer, and etching an etch back layer and part of the dielectric layer under the conditions where the etch back layer and the dielectric layer are thinned at the same rate, wherein forming the comb-shaped electrodes includes: forming a lower resist layer on the piezoelectric substrate; forming an upper resist layer on the lower resist layer; patterning the upper and lower resist layers with a developer with respect to which a solubility of the lower resist layer is higher than that of the upper resist layer to form a lower resist pattern and an upper resist pattern on the lower resist pattern so that a periphery of the lower resist pattern lies within a periphery of the upper resist pattern; depositing an electrode material over an entire surface of the piezoelectric substrate that has the upper resist pattern and the lower resist pattern formed thereon; and removing the upper resist pattern and the lower resist pattern to pattern the electrode material, thereby forming the comb-shaped electrode by lift-off.