A parametric analysis of microbolometer pixel designs

As microbolometer pixel dimensions for infrared imagers continue to decrease, the need for full-wave analysis in the design process is enhanced. Using reflectance as the validation point, an electromagnetic model of a dual-layer microbolometer pixel design was created for a 25 mu m pixel design, and an in-depth study of the design was performed. With this model validated, further explorations were completed with a reduced size pixel. While simulating multiple variations of specific parameters, such as bridge thickness, upper and lower cavity heights, and different absorber configurations, a new evaluation metric of dissipated power in the structure was studied. This metric, provided by finite element analysis, provides great insight into absorption properties within the microbolometer structure, properties that cannot be directly measured but that are critical to the functionality of the pixel design. In this paper parametric analysis of microbolometer pixel designs are presented via both reflectance and dissipated power full-wave analysis.