Bulk acoustic wave resonator structure i.e. double bulk acoustic resonator structure, for ladder filter of e.g. portable communication device, has top electrode placed over piezoelectric layer, and bridge placed between two electrodes

摘要

The structure i.e. double bulk acoustic resonator (DBAR) structure (100), has an electrode (107) placed over a substrate (105) and another electrode (111) placed over a piezoelectric layer (108) placed on the former electrode. Another piezoelectric layer (112) is placed over the latter electrode. A top electrode (101) is placed over the latter piezoelectric layer. A bridge is placed between the former electrode and the top electrode. The bridge comprises a fill material i.e. non-etchable borosilicate glass (NEBSG). The latter electrode is a bulk acoustic wave (BAW) resonator.