Temperature compensated acoustic resonator device having thin seed interlayer

Abstract

An acoustic resonator device includes a composite first electrode disposed over a substrate; a piezoelectric layer disposed on the composite first electrode, the piezoelectric layer including a piezoelectric material doped with scandium for improving piezoelectric properties of the piezoelectric layer; and a second electrode disposed on the piezoelectric layer. The composite first electrode includes a base electrode layer disposed over the substrate; a temperature compensation layer disposed on the base electrode layer; a seed interlayer disposed on the temperature compensation layer, the seed interlayer having a thickness between about 5 Å and about 150 Å; and a conductive interposer layer disposed on at least the seed interlayer, at least a portion of the conductive interposer layer contacting the base electrode layer. The piezoelectric layer has a negative temperature coefficient and the temperature compensation layer has a positive temperature coefficient that at least partially offsets the negative temperature coefficient of the piezoelectric layer.

Dependencies are inferred from the claim text.