Summary: IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 54, NO. 8, AUGUST 2007 2017
Low-Impedance VHF and UHF Capacitive Silicon
Bulk Acoustic Wave Resonators--Part I:
Concept and Fabrication
Siavash Pourkamali, Member, IEEE, Gavin K. Ho, Student Member, IEEE, and Farrokh Ayazi, Senior Member, IEEE
Abstract--This paper presents high-performance high-
frequency single-crystal silicon (SCS) capacitive resonators.
Long and thick bulk-micromachined resonating block structures,
which are referred to as "silicon bulk acoustic wave resonator"
(SiBAR), are fabricated using the high-aspect-ratio poly and
single crystalline silicon" (HARPSS) fabrication process on
silicon-on-insulator (SOI) substrates. Such resonators operate
in their horizontal width extensional modes with quality factors
in the range of 10 000100 000. With their comparatively large
electrode area and deep-submicrometer capacitive transduction
gaps, such resonators have demonstrated comparatively low
impedances for capacitive resonators that are well within
the desired range for high-frequency electronic applications.
Sub-kilo-Ohm total electrical resistances and extracted motional
resistance as low as 200 are demonstrated for the fundamental