Patent ID: 7435613

Claim:
A method of forming a thin film acoustic device, the method comprising the steps of: forming a base electrode; forming a second electrode; forming a piezoelectric film between the base electrode and the second electrode to enable application of an electric field to the piezoelectric film, wherein the foregoing is accomplished by: providing a substrate; depositing and patterning a first conductive layer to define the base electrode with an edge region having a first height relative to the substrate; and placing a second layer of material over the substrate with a portion positioned along the edge region of the base electrode, said portion having a height relative to the substrate so as to eliminate or substantially reduce a step along the base electrode edge region relative to the first height, wherein the second layer of material is formed by: depositing a non-conducting layer after patterning the first conductive layer; and planarizing the non-conducting layer by chemical mechanical polishing, polymer planarization, or polymer reflow with liftoff.