Enhanced thermal sensitivity of MEMS bolometers integrated with nanometer-scale hole array structures

Abstract

We have fabricated two-dimensional nanometer-scale hole array structures on GaAs doubly-clamped microelectromechanical system (MEMS) beam resonators to modulate their thermal properties. Owing to the reduction in the thermal conductance of the MEMS beams by introducing the hole array structures, the nano-porous MEMS bolometers show 2-3 times larger thermal sensitivities than the unpatterned reference sample. Furthermore, since the heat capacitance of the MEMS beams is also reduced by introducing the hole array, the thermal decay time of the patterned MEMS beams is increased only by about 30-50%, demonstrating the effectiveness of the hole array structures for enhancing the thermal sensitivities of bolometers without significantly deteriorating their operation bandwidths.