[18p-Z24-1~14] 13.4 Si processing /Si based thin film / MEMS / Equipment technology

▲ [18p-Z24-14] Effect of surface step structures on the thermal responsivity of MEMS bolometers

〇(D)Boqi Qiu¹, Ya Zhang², Naomi Nagai¹, Kazuhiko Hirakawa¹ (1.IIS/INQIE, Univ. of Tokyo, 2.TUAT)

Keywords:MEMS, Bolometer, Responsivity

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. When the doubly clamped MEMS beam is heated by THz radiation, a thermal stress is induced in the MEMS beam and its resonance frequency decreases. We use piezoelectric capacitors on both ends of the MEMS beam to drive and detect the vibration of the beam. The present device detects the frequency reduction induced by heating and works as a very sensitive thermometer. Previously, we found that initial beam deflection reduces the thermal responsivity of the MEMS bolometers. To suppress the initial beam deflection, we preloaded a tensile strain in the MEMS beam. However, we found that although the deflection is reduced, it still remains. In this report we show that a significant part of the residual beam deflection is induced by the step structure on the beam surface.