A surface micromachined amorphous Ge x Si 1-x O y bolometer for thermal imaging applications

Abstract

We present characterization of a surface micro-machined microbolometer featuring a number of unique features. The active resistor layer is amorphous Ge_xSi_1-xO_y grown by reactively co-sputtering Ge and Si in an oxygen background. Complete control over Ge, Si, and O content using this technique allows control of both temperature coefficient of resistance and resistivity of the material, enabling optimization of material characteristics for bolometer applications. The resistor layer is combined with top and bottom NiCr metalization to form a tuned absorber for 10 μm radiation, eliminating requirements for additional absorber layers or for carefully controlled air gap thickness. Characterization of device noise and performance is presented.