Method for manufacturing a BAW resonator with high quality factor

摘要

The method involves depositing an upper silicon oxide layer (37a) of a Bragg mirror (37), where the upper silicon oxide layer extends between one of contact pads connected to an electrode of a piezoelectric resonator (5) and a substrate (3). The Bragg mirror includes an upper tungsten layer (37b) extending between the pad and the substrate. Unevenness of thickness of the upper silicon oxide layer related to a deposition process is decreased by ion itching such that the layer has same thickness than 1 percent at the level of each of the contact pads. An independent claim is also included for a wafer for a bulk acoustic wave resonator.