US Patent 9577603 Solidly mounted acoustic resonator having multiple lateral features

A solidly mounted resonator (SMR) includes an acoustic resonator on a substrate, the acoustic resonator having multiple acoustic impedance layers having different acoustic impedances, respectively. The SMR further includes a bottom electrode on a top acoustic impedance layer of the plurality of acoustic impedance layers, a piezoelectric layer on the bottom electrode, a top electrode on the piezoelectric layer, and multiple lateral features on a surface of the top electrode. The lateral features include multiple stepped structures.