Layer acoustic wave device and method of making the same
AssigneeRF Micro Devices, Inc.
InventorKushal Bhattacharjee
Life of this patent
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Abstract
The present invention provides a layer acoustic wave device that is formed without requiring a bonding process to attach a secondary substrate. In particular, the layer acoustic wave device is formed from a substrate, an interdigital transducer created on the substrate, a dielectric layer formed over the interdigital transducer and substrate, and at least one isolation layer formed over the dielectric layer. The at least one isolation layer has sufficient properties to minimize particle displacement on a top surface of the at least one isolation layer. The at least one isolation layer has a greater acoustic impedance than that of the dielectric layer.
Claims19
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.
Dependencies are inferred from the claim text.