Patent ID: 8841819
Filing Date: 2014-09-23
Classification: H03H

Abstract:
1. An acoustic wave device comprising: a substrate; a first piezoelectric thin film resonator provided on the substrate and including a first lower electrode, a first upper electrode and a first piezoelectric film sandwiched between the first lower and upper electrodes; a decoupler film provided on the first upper electrode; and a second piezoelectric thin film resonator provided on the decoupler film and including a second lower electrode, a second upper electrode and a second piezoelectric film sandwiched between the second lower and upper electrodes, wherein the first piezoelectric film and the second piezoelectric film comprise aluminum nitride and include an element increasing a piezoelectric constant of the aluminum nitride, and wherein an amount of the element included in the first piezoelectric film is smaller than that of the element included in the second piezoelectric film.