[20p-212A-1~16] 3.9 Terahertz technologies

▲ [20p-212A-3] Effect of the surface step structures on the responsivity of the MEMS terahertz bolometers

〇(M2)Boqi Qiu¹, Ya Zhang¹, Naomi Nagai¹, Kazuhiko Hirakawa^1,2 (1.IIS, Univ. of Tokyo, 2.INQIE, Univ. of Tokyo)

Keywords:MEMS, terahertz, bolometer

We reported a room temperature, all electrical driving and detecting, very sensitive thermometer using a GaAs doubly clamped microelectromechanical (MEMS) beam resonator for bolometer applications. When the MEMS beam is heated by THz radiation, a compressive strain is generated in the beam due to thermal expansion and a resonance frequency shift can be detected by the piezoelectric effect. For an ideal flat beam, when the compressive strain increase to Euler’s critical load, the MEMS beam is buckled, the resonance frequency decreases to zero and then start to increase, and the frequency-strain curve shows a sharp dip around the critical load. However, for beams with a deflection, the resonance frequency does not reach zero at the critical load, and the slope of frequency decrease becomes smaller, indicating a lower responsivity. In this work, we report that the beam deflection is induced by the mesa structure on the beam surface. Furthermore, samples of different surface structure are fabricated to clarify the issue.