Method to control BAW resonator top electrode edge during patterning

A piezoelectric resonator comprising:

• a. a bottom electrode;
• b. a piezoelectric layer coupled to the bottom electrode;
• c. a top electrode coupled to the piezoelectric layer, wherein the top electrode comprises a bottom metal layer and a top metal layer configured such that a perimeter edge of the top metal layer is recessed relative to a perimeter edge of the bottom metal layer;
• d. a passivation layer coupled to the top electrode, wherein the passivation layer includes an etched portion configured to provide a contact point with the top electrode, further wherein the passivation layer is further configured to isolate a remaining portion of the top electrode;
• and
• e. an interconnect metal layer coupled to the top electrode at the contact point through the etched portion of the passivation layer.

A piezoelectric resonator comprising:

• a. a bottom electrode;
• b. a piezoelectric layer coupled to the bottom electrode;
• c. a top electrode coupled to the piezoelectric layer, wherein the top electrode comprises a bottom metal layer and a top metal layer configured such that a perimeter portion of a top surface of the bottom metal layer is uncovered by the top metal layer;
• and
• d. a passivation layer coupled to the top electrode such that the top metal layer and the bottom metal layer are isolated from a subsequent metal etch step.