Patent ID: 9461616
Filing Date: 2016-10-04
CPC Classification: H03H

Claim Text:
1. A bulk wave resonator, comprising: a substrate; a frame member layer on the substrate; a first ScAlN protective layer on the frame member and defining a space between the substrate, the frame member and the first ScAlN protective layer; a first electrode on the first ScAlN protective layer; an aluminum nitride film containing scandium on the first electrode and including a portion acoustically isolated from a surface of the substrate and partly separated from the surface of the substrate by the space; a second electrode on the aluminum nitride film and extending over the space, the second electrode overlapping with the first electrode with the aluminum nitride film containing scandium interposed therebetween, and the overlap between the first electrode and the second electrode is a piezoelectric vibrating portion; and a second ScAlN protective layer covering the second electrode and the aluminum nitride film, the scandium content of the aluminum nitride film ranges from 5 to 43 atomic percent when the scandium and aluminum of the aluminum nitride film are 100 atomic percent.