Coupled Physics Analyses of VOx-Based, Three-Level Microbolometer

As an uncooled infrared (IR) detector, a vanadium-oxide(VOx)-based microbolometer plays a very important role in the emerging IR imaging technology due to its low cost, small size, simple system-architecture, and etc. As the thermal conductance comes into conflict with the fill factor in the conventional two-level microbolometer structure, a three-level microbolometer structure is proposed using the same active material of VOx. Coupled physics analyses of the proposed three-level device structure were carried out thermo-mechanically and electrostatically. The results of steady-state analyses show that the temperature increase and the resistance change amount to 29.3 mK/nW and 0.079%/nW respectively, when the microbolometer is exposed to IR incidence. From the transient coupled physics analyses, the thermal conductance and time constant of the device were obtained as 3.4 x 10(-8) W/K and 4.53 ms respectively. The obtained parameters are comparable to those of a two-level structure having 4 times larger area.