Abstract

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 [1]. When the MEMS beam is heated by radiation, its resonance frequency is shifted by a temperature rise and the signal is detected by the piezoelectric effect [2]. Increasing the quality factor (Q) of the mechanical resonance is advantageous for improving performance of the MEMS bolometer. It was reported that introduction of tensile strain induced by lattice mismatch between GaNAs and GaAs improves the Q-factor of the MEMS resonators by 30 times, when compared with that of unstrained GaAs resonators, and that the resonance frequency is significantly enhanced [3]. However, since nitrogen acts as deep levels in GaAs, it is very difficult to create a conductive layer in the GaAs MEMS beam and form piezoelectric capacitors to realize electrical driving and detection. Therefore, in this work, we introduced phosphorus, instead of nitrogen, to induce a preloaded tensile strain in the MEMS beam and investigated how the tensile strain influence the behavior.

© 2017 Japan Society of Applied Physics, Optical Society of America