Patent ID: 9559291
Date: 2017-01-31
CPC Classifications: H01L,H03H,Y10T

Claim:
1. An acoustic wave device comprising: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across the piezoelectric film, the upper electrode including a first conductive film and a second conductive film formed on the first conductive film; an insulating film sandwiched between the first conductive film and the second conductive film and having a temperature coefficient of an elastic constant opposite in sign to a temperature coefficient of an elastic constant of the piezoelectric film; and a third conductive film formed on edge surfaces of the insulating film and the second conductive film and causing electrical short circuits between the first conductive film and the second conductive film, wherein an outer periphery of the piezoelectric film at an extracting wiring side of the lower electrode is located further in than an edge surface of the insulating film.