A piezoelectric resonator include a multi-layer top electrode. The
multi-layer top electrode includes at least a top metal layer and a
bottom metal layer. A top metal layer edge is recessed compared to a
bottom metal layer edge allowing conformal deposition of a passivation
layer. The passivation layer covers and protects the underlying layers
from subsequent etching, thereby preventing etch undercut of the top
electrode. In some embodiments, the multi-layer top electrode is
configured as a bi-layer. In other embodiments, an extra layer is
configured between the top metal layer and the bottom metal layer, for
example a shunt load layer.