Inventors:
James F. Black - Newington CT
Richard A. Courtney - Vienna VA
Thomas W. Grudkowski - Glastonbury CT
Philip T. Norusis - Falls Church VA
Harry R. Wood - Gaithersburg MD
Assignee:
United Technologies Corporation - Hartford CT
International Classification:
H03H 917
H03H 9205
H03H 950
H03H 956
Abstract:
A substrate (10) is thinned to provide a membrane (12) on which are disposed a counter electrode (20), a film of low conductivity piezoelectric material (22) and a top electrode (24) to form a half wavelength, bulk mode resonator employing a longitudinal acoustic wave. A second top electrode (25) provides a second resonator acoustically coupled to the first, to form a filter. Piezoelectric films include zinc oxide, and aluminum nitride; substrates include silicon and aluminum oxide. A buffer layer (18), such as silicon dioxide may assist in preventing surface aberations and providing proper crystallographic orientation.