US 12,081,194 B2
Top electrodes and dielectric spacer layers for bulk acoustic wave resonators
Alireza Tajic, Winter Springs, FL (US); Paul Stokes, Orlando, FL (US); and Robert Aigner, Ocoee, FL (US)
Assigned to Qorvo US, Inc., Greensboro, NC (US)
Filed by Qorvo US, Inc., Greensboro, NC (US)
Filed on Mar. 29, 2023, as Appl. No. 18/192,312.
Application 18/192,312 is a continuation of application No. 17/821,906, filed on Aug. 24, 2022, granted, now 11,722,119.
Application 17/821,906 is a continuation of application No. 16/525,858, filed on Jul. 30, 2019, granted, now 11,502,667, issued on Nov. 15, 2022.
Claims priority of provisional application 62/792,113, filed on Jan. 14, 2019.
Prior Publication US 2023/0231535 A1, Jul. 20, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H03H 9/13 (2006.01); H03H 9/02 (2006.01); H03H 9/17 (2006.01); H03H 9/54 (2006.01); H10N 30/87 (2023.01); H10N 30/88 (2023.01)
CPC H03H 9/132 (2013.01) [H03H 9/02062 (2013.01); H03H 9/02086 (2013.01); H03H 9/173 (2013.01); H03H 9/175 (2013.01); H03H 9/54 (2013.01); H10N 30/87 (2023.02); H10N 30/883 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A bulk acoustic wave (BAW) resonator comprising:
a bottom electrode;
a piezoelectric layer over the bottom electrode;
a top electrode over the piezoelectric layer, the top electrode defining a central region, an inner region that extends about a periphery of the central region, and a border (BO) region such that the inner region is between the central region and the BO region; and
a dielectric spacer layer arranged between the top electrode and the piezoelectric layer at the BO region, the dielectric spacer layer being in contact with the piezoelectric layer under the top electrode at the BO region;
wherein a height profile is defined across the central region, the inner region, and the BO region, and the height profile relative to the piezoelectric layer decreases from the BO region to the inner region and the height profile increases from the inner region to the central region.