Patent ID: 7619347

Claim:
A layer acoustic wave device comprising: a piezoelectric substrate having an upper surface; a metallic interdigital transducer formed on the upper surface of the piezoelectric substrate; a dielectric layer having a first acoustic impedance and formed over the upper surface of the piezoelectric substrate and the metallic interdigital transducer; a deposited or grown first isolation layer having a second acoustic impedance and over the dielectric layer, the second acoustic impedance being greater than the first acoustic impedance, wherein the deposited or grown first isolation layer is configured to confine acoustic energy in the dielectric layer; a deposited or grown second isolation layer having a third acoustic impedance and over the deposited or grown first isolation layer; and a deposited or grown third isolation layer having a fourth acoustic impedance and over the deposited or grown second isolation layer, wherein the fourth acoustic impedance is greater than the third acoustic impedance.