Modeling, design and characterization of surface micromachined polysilicon microbolometers

Resistive microbolometers are today´s front-runners in the emerging field of uncooled IR thermal sensors. The microbolometer sensor pixel is based on a thermally isolated structure that absorbs IR radiation and as a result undergoes a temperature increase. The structure includes a temperature sensitive resistor, so that under bias conditions the current or the voltage on the sensor change due to incident radiation. The thermal isolation can be obtained by micromachining a sacrificial layer under a suspended resistor. Usually, the gas thermal conduction is reduced by encapsulation under vacuum conditions. In this work we modeled and designed polysilicon microbolometers that were fabricated using a surface micromachining process of MUMPS.