US 12,088,282 B2
Structure and manufacturing method of surface acoustic wave filter with back electrode of piezoelectric layer
Guojun Weng, Shenzhen (CN); and Gongbin Tang, Shenzhen (CN)
Assigned to Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed by Shenzhen Newsonic Technologies Co., Ltd., Shenzhen (CN)
Filed on Jul. 13, 2023, as Appl. No. 18/351,558.
Application 18/351,558 is a division of application No. 17/933,070, filed on Sep. 16, 2022.
Prior Publication US 2023/0361758 A1, Nov. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H03H 9/64 (2006.01); H03H 3/08 (2006.01); H03H 9/02 (2006.01); H03H 9/05 (2006.01); H03H 9/10 (2006.01)
CPC H03H 9/6423 (2013.01) [H03H 3/08 (2013.01); H03H 9/02897 (2013.01); H03H 9/059 (2013.01); H03H 9/1092 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A surface acoustic wave (SAW) filter, comprising:
a bottom substrate;
a piezoelectric layer disposed above the bottom substrate, the piezoelectric layer having a bottom surface facing the bottom substrate and a top surface opposite to the bottom surface;
a lower cavity disposed below the piezoelectric layer;
an upper cavity disposed above the piezoelectric layer;
a back electrode disposed on the top surface of the piezoelectric layer and exposed in the upper cavity; and
an interdigital transducer (IDT) disposed on the bottom surface of the piezoelectric layer, and having an interdigital portion exposed in the lower cavity.