US 11,750,172 B2
Multilayer piezoelectric substrate
Rei Goto, Osaka (JP); Keiichi Maki, Suita (JP); and Gong Bin Tang, Moriguchi (JP)
Assigned to SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed by SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed on Aug. 14, 2020, as Appl. No. 16/993,551.
Claims priority of provisional application 62/889,613, filed on Aug. 21, 2019.
Prior Publication US 2021/0058057 A1, Feb. 25, 2021
Int. Cl. H03H 9/02 (2006.01); H03H 9/25 (2006.01); H03H 9/64 (2006.01)
CPC H03H 9/02574 (2013.01) [H03H 9/02559 (2013.01); H03H 9/02834 (2013.01); H03H 9/25 (2013.01); H03H 9/6406 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A surface acoustic wave (SAW) resonator comprising:
a multilayer piezoelectric substrate, the multilayer piezoelectric substrate including a layer of piezoelectric material having a lower surface bonded to an upper surface of a layer of a second material different from the piezoelectric material that improves the temperature stability and reliability of the SAW resonator, the upper surface of the layer of the second material including a trap rich layer which reduces a parasitic surface conductivity of the layer of second material, the layer of piezoelectric material being bonded to the layer of the second material with an adhesive material, a layer of silicon dioxide disposed between the layer of piezoelectric material and the layer of the second material, the lower surface of the layer of piezoelectric material directly bonded to an upper surface of the layer of silicon dioxide, the upper surface of the layer of second material directly bonded to a lower surface of the layer of silicon dioxide, a lower surface of the layer of the second material being roughened;
a plurality of interdigital transducer electrodes disposed on the multilayer piezoelectric substrate; and
a layer of dielectric material disposed on an upper surface of the interdigital transducer electrodes and the multilayer piezoelectric substrate.