Presentation Information

[25a-11E-7]SOI MEMS resonators with piezoresistive readout for uncooled terahertz sensing

〇Mirai Iimori1, Kazuki Ebata1, Ryotaro Takeuchi1, Isao Morohashi2, Kazusuke Maenaka3, Kazuhiko Hirakawa4, Ya Zhang1 (1.Inst. of Eng., Tokyo Univ. of Agri.&Techno., 2.NICT, 3.Univ. of Hyogo, 4.Univ. of Tokyo)

Keywords:

MEMS,terahertz,sensor

This paper presents the development of SOI MEMS resonators with piezoresistive readout for terahertz (THz) bolometers. Conventional MEMS bolometers using GaAs suffer from sensitivity loss due to the material's polarity. SOI offers an alternative material with a broader spectral range but lacks piezoelectricity for excitation and readout.
This work proposes a fabrication process using Spin-on Dopant (SOD) to create piezoresistive structures on SOI beams. The process involves selective doping of the SOI layer and deposition of metal contacts for both electrostatic actuation and current measurement. Initial tests demonstrate successful excitation and readout of the MEMS beam vibrations. By applying an AC voltage, a current change of 170 nA was observed at the resonant frequency, indicating a piezoresistance sensitivity of 3.2 ppm/nm.
These findings suggest the potential of using SOI MEMS resonators with piezoresistive readout for uncooled, sensitive, and fast THz bolometers.