Method of forming electrode for saw device

摘要

A method of forming an electrode for a surface acoustic wave (SAW) device comprises the steps of forming an alloy film ( 32 ) made of aluminum (Al) and magnesium (Mg) on a substrate ( 31 ) and selectively etching the alloy film ( 32 ) by using a gaseous mixture composed of BCl₃, Cl₂, and N2 to form the electrode such that the electrode has at least one sidewall polymer film ( 33 ). The method controls the production of hillocks and voids to provide high withstand voltage.