Patent ID: 8610333

Claim:
An acoustic wave device, comprising: (a) a substrate; (b) one or more series acoustic wave resonators, each series acoustic wave resonator having a bottom electrode formed on the substrate, a piezoelectric layer formed on the bottom electrode, a top electrode formed on the piezoelectric layer, and a passivation layer formed on the top electrode; and (c) one or more shunt acoustic wave resonators, each shunt acoustic wave resonator having a bottom electrode formed directly on the substrate, a mass load layer formed directly on the bottom electrode, a piezoelectric layer formed directly on the mass load layer, a top electrode formed directly on the piezoelectric layer, and a passivation layer formed on the top electrode, such that the bottom electrode, the mass load layer, the piezoelectric layer, the top electrode and the passivation layer are sequentially stacked over the substrate, wherein the bottom electrode comprises one of tungsten, molybdenum, platinum, ruthenium, iridium, titanium tungsten, titanium, and a combination of them, wherein the mass load layer comprises one of tungsten, molybdenum, platinum, tantalum, ruthenium, iridium, titanium tungsten, silicon nitride and silicon carbide, and wherein the mass load layer is substantially in contact with the bottom electrode, wherein the one or more series acoustic wave resonators and the one or more shunt acoustic wave resonators are coupled to each other in one of lattice and ladder configurations.