[13p-N105-1~14] 3.9 Terahertz technologies

▲ [13p-N105-13] Piezoresistive detection of MEMS beam resonators for THz bolometer applications

〇Boqi Qiu¹, Nobuaki Watanabe¹, Ya Zhang², Naomi Nagai¹, Kazuhiko Hirakawa¹ (1.IIS/INQIE UTokyo, 2.TUAT)

Keywords:MEMS, Bolometer, Piezoresistive effect

Terahertz (THz) detectors are one of the crucial components in the THz technologies. Recently, we reported a room temperature, high-speed THz bolometer using a GaAs doubly clamped MEMS beam resonator. The MEMS bolometer detects the frequency reduction induced by heating of the beam and works as a very fast and sensitive thermometer. We use piezoelectric capacitors on both ends of the MEMS beam to drive and detect the vibration of the beam. However, the output voltage from the piezoelectric capacitor is very small (typically; ~1 μV), because it is shunted by the stray capacitance of measurement cables. We need to use a buffer amplifier to suppress the effects of stray capacitance. In this report, we propose to use the piezoresistive detection scheme, instead of the piezocapacitive effect, to detect the MEMS beam vibration.