SURFACE ACOUSTIC WAVE DEVICE

摘要

Disclosed is a surface acoustic wave device wherein an insulator layer is so formed as to cover an IDT electrode and the surface of the insulator layer is planarized. In such a surface acoustic wave device, the electrode can have a sufficiently large reflection coefficient. Specifically disclosed is a surface acoustic wave device wherein a plurality of grooves (1b) are formed in the upper surface of a piezoelectric substrate (1), and those grooves (1b) are filled with an electrode material, thereby forming electrode films (3) which constitute IDT electrodes. In this surface acoustic wave device, an insulator layer (4) such as an SiO₂ film is so formed as to cover the piezoelectric substrate (1) and the electrode films (3) formed in the grooves (1b), and the surface of the insulator layer (4) is planarized.