Acoustic wave device

摘要

An acoustic wave device includes: a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film located between the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein an outer periphery of an uppermost piezoelectric film out of the at least two piezoelectric films in a region in which the lower electrode and the upper electrode face each other is positioned further in than an outer periphery of the upper electrode.

主权项

1. An acoustic wave device comprising:
a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film located between the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein outer peripheries of upper and lower surfaces of an uppermost piezoelectric film out of the at least two piezoelectric films in a region in which the lower electrode and the upper electrode face each other are positioned further in than an outer periphery of the upper electrode, wherein in a region in which the outer peripheries of the upper and lower surfaces of the uppermost piezoelectric film are positioned further in than the outer periphery of the upper electrode, outer peripheries of upper and lower surfaces of a lowermost piezoelectric film out of the at least two piezoelectric films are positioned further out than the outer periphery of the upper electrode; and wherein no electrode is formed between the lower electrode and the upper electrode.