Low Loss Intermediate-Frequency Resonator Filter Using Shear Horizontal Type Leaky Surface Acoustic Wave on α-Phase Heavy Metal Film/Quartz
Year: 2004
Type: article
Abstract: By applying a new shear horizontal (SH)-type leaky surface acoustic wave (LSAW) excited by interdigital transducers (IDTs) and reflectors made of Ta or W on an ST-cut 90°X-propagation (direction perpendicular to X-axis) quartz substrate, we succeeded in fabricating very small resonator filters (1/5–1/4 of conventional device sizes). However, the Ta and W films used in our filters were β-Ta and β-W, which have resistances higher than that of an Al film. α-Ta and α-W films with very low resistivities have been successfully deposited in place of β-Ta and β-W films. The insertion loss of resonator filters consisting Ta- or W-electrode/ST-90°X quartz has been improved by 1.5–8 dB using the α-Ta or the α-W film electrode.
DOI: 10.1143/jjap.43.3047
Authors: Michio Kadota, Eiichi Takata, Masatoshi Nakagawa, Makoto Tose, Yasuji Yamamoto
Institution: Murata (Japan)
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2004012475