US 11,863,156 B2
Acoustic wave device including multi-layer interdigital transducer electrodes
Tomohiro Iwasaki, Otsu (JP); Hiroyuki Nakamura, Osaka-Fu (JP); Toru Yamaji, Nagaokakyou (JP); Mitsunori Miyanari, Osaka-Fu (JP); Masahiro Yasumi, Osaka-Fu (JP); and Shoji Okamoto, Osaka-Fu (JP)
Assigned to SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD., Kadoma (JP)
Filed by SKYWORKS FILTER SOLUTIONS JAPAN CO., LTD., Kadoma (JP)
Filed on Aug. 20, 2019, as Appl. No. 16/545,037.
Application 16/545,037 is a continuation of application No. 15/332,279, filed on Oct. 24, 2016, granted, now 10,439,585.
Application 15/332,279 is a continuation of application No. 14/176,149, filed on Feb. 10, 2014, granted, now 9,496,846, issued on Nov. 15, 2016.
Claims priority of application No. 2013-027414 (JP), filed on Feb. 15, 2013; application No. 2013-047493 (JP), filed on Mar. 11, 2013; and application No. 2013-187919 (JP), filed on Sep. 11, 2013.
Prior Publication US 2019/0379346 A1, Dec. 12, 2019
Int. Cl. H03H 9/02 (2006.01); H03H 3/10 (2006.01); H03H 9/13 (2006.01); H03H 3/08 (2006.01)
CPC H03H 9/02559 (2013.01) [H03H 3/08 (2013.01); H03H 3/10 (2013.01); H03H 9/02834 (2013.01); H03H 9/02937 (2013.01); H03H 9/02984 (2013.01); H03H 9/131 (2013.01); H03H 9/132 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A surface acoustic wave device comprising:
a substrate;
an interdigital transducer (IDT) electrode disposed on the substrate, the IDT electrode including a lower electrode layer having a lower surface in contact with an upper surface of the substrate and an upper electrode layer having a lower surface defining a base in contact with an upper surface of the lower electrode layer, side surfaces of the lower electrode layer being substantially perpendicular to the upper surface of the substrate, side surfaces of the upper electrode layer being disposed at an acute angle relative to the upper surface of the substrate; and
a layer of dielectric material disposed on the upper surface of the substrate and the IDT electrode, the layer of dielectric material including an upper surface having projections disposed over fingers of the IDT electrode, a largest angle among angles formed by upper surfaces of the projections being smaller than the acute angle.