US 12,316,296 B2
Methods related to gradient raised frames in film bulk acoustic resonators
Jiansong Liu, Irvine, CA (US); Kwang Jae Shin, Yongin (KR); Jae Hyung Lee, Seoul (KR); Benjamin Paul Abbott, Irvine, CA (US); and Chun Sing Lam, San Jose, CA (US)
Assigned to Skyworks Global Pte. Ltd., Singapore (SG)
Filed by SKYWORKS GLOBAL PTE. LTD., Singapore (SG)
Filed on Jun. 28, 2024, as Appl. No. 18/759,178.
Application 18/759,178 is a continuation of application No. 17/018,847, filed on Sep. 11, 2020, granted, now 12,028,041.
Claims priority of provisional application 62/900,415, filed on Sep. 13, 2019.
Prior Publication US 2024/0421793 A1, Dec. 19, 2024
Int. Cl. H03H 9/02 (2006.01); H03H 3/02 (2006.01); H03H 9/17 (2006.01); H03H 9/56 (2006.01)
CPC H03H 9/0211 (2013.01) [H03H 3/02 (2013.01); H03H 9/174 (2013.01); H03H 9/564 (2013.01); H03H 2003/023 (2013.01); Y10T 29/42 (2015.01); Y10T 29/4908 (2015.01)] 20 Claims
OG exemplary drawing
 
1. A method for fabricating a film bulk acoustic resonator device, the method comprising:
forming a first metal layer over a substrate;
forming a piezoelectric layer;
forming a second metal layer, the piezoelectric layer positioned between the first and second metal layers, the first metal layer, the second metal layer, and the piezoelectric layer forming an active region; and
forming a gradient raised frame implemented relative to one of the first and second metal layers and configured to improve reflection of lateral mode waves and to reduce conversion of main mode waves into lateral mode waves, the gradient raised frame including a gradient portion that interfaces with one or more of the first metal layer, the second metal layer, or the piezoelectric layer without passing through the active region.