Fabrication of film bulk acoustic resonators on silicon <110> wafers using crystal-orientation-dependent anisotropic etching

摘要

A film bulk acoustic resonator formed on a substrate includes a layer of piezoelectric material having a first major surface, and a second major surface sandwiched between a first conductive and a second conductive layer. The substrate on which the film bulk acoustic resonator is formed has an opening therein which exposes the first conductive layer of the film bulk acoustic resonator. The opening is substantially in the shape of a parallelogram having a first pair of parallel sides and a second pair of parallel sides. One of the first pair of parallel sides makes an angle at other than 90 degrees with one of the second pair of parallel sides.