Summary: JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 12, NO. 4, AUGUST 2003 487
High-Q Single Crystal Silicon HARPSS Capacitive
Beam Resonators With Self-Aligned Sub-100-nm
Transduction Gaps
Siavash Pourkamali, Student Member, IEEE, Akinori Hashimura, Student Member, IEEE,
Reza Abdolvand, Student Member, IEEE, Gavin K. Ho, Student Member, IEEE, Ahmet Erbil, and
Farrokh Ayazi, Member, IEEE
Abstract--This paper reports on the fabrication and charac-
terization of high-quality factor (Q) single crystal silicon (SCS)
in-plane capacitive beam resonators with sub-100 nm to submicron
transduction gaps using the HARPSS process. The resonating el-
ement is made of single crystal silicon while the drive and sense
electrodes are made of trench-refilled polysilicon, yielding an all-
silicon capacitive microresonator. The fabricated SCS resonators
are 20­40 m thick and have self-aligned capacitive gaps. Ver-
tical gaps as small as 80 nm in between 20 m thick silicon struc-
tures have been demonstrated in this work. A large number of
clamped-free and clamped­clamped beam resonators were fabri-
cated. Quality factors as high as 177 000 for a 19 kHz clamped-free
beam and 74 000 for an 80 kHz clamped­clamped beam were mea-

Source: Ayazi, Farrokh - School of Electrical and Computer Engineering, Georgia Institute of Technology

Collections: Engineering