Method of manufacturing elastic wave device

摘要

A method for manufacturing an elastic wave device includes a step of preparing a supporting substrate, a step of forming a high-acoustic-velocity film on the supporting substrate and in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film, a step of forming a low-acoustic-velocity film on the high-acoustic-velocity film and in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film, a step of forming the piezoelectric film on the low-acoustic-velocity film, and a step of forming an IDT electrode on a surface of the piezoelectric film.

主权项

1. A method for manufacturing an elastic wave device comprising:
a step of preparing a supporting substrate; a step of forming a high-acoustic-velocity film, in which an acoustic velocity of a bulk wave propagating therein is higher than an acoustic velocity of an elastic wave propagating in a piezoelectric film; a step of forming a low-acoustic-velocity film, in which an acoustic velocity of a bulk wave propagating therein is lower than an acoustic velocity of a bulk wave propagating in the piezoelectric film; a step of forming the piezoelectric film; and a step of forming an IDT electrode; wherein the high-acoustic-velocity film is located on the supporting substrate; the low-acoustic-velocity film is located on the high-acoustic-velocity film; the piezoelectric film is located on the low-acoustic-velocity film; the IDT electrode is located on a surface of the piezoelectric film; and a thickness of the low-acoustic-velocity film located on the high-acoustic-velocity film and under the piezoelectric film is in a range of about 0.1λ to about 0.5λ, where λ is a wavelength of an elastic wave determined by an electrode period of the IDT electrode.