METHOD AND SYSTEM FOR WAFER-LEVEL TUNING OF BULK ACOUSTIC WAVE RESONATORS AND FILTERS

摘要

A method and system for tuning a bulk acoustic wave device at the wafer level by adjusting the thickness of the device. In particular, the thickness of the device has a non-uniformity profile across the device surface. A mask with an aperture is placed over the device surface and a particle beam is applied over the mask so as to allow part of the particle beam to make contact with the device surface at a localized area beneath the aperture. The particles that pass through the aperture are deposited on the device surface to add material on the device surface, thereby increasing the surface thickness to correct for the thickness non-uniformity. Alternatively, the particles that pass through the aperture remove part of the device surface in an etching process, thereby reducing the surface thickness. Prior to thickness adjustment, a frequency measurement device or thickness measurement device is used to map the device surface for obtaining the non-uniformity profile.