This work describes a fabrication process for the manufacturing of a surface micromachined microbridge-type bolometer for infrared thermal imaging applications, which is compatible with any standard complementary metal-oxide-semiconductor process. The bolometer uses a high resistivity amorphous GexSi1-xOy active layer incorporated in a self-absorbing structure for infrared radiation, requiring no additional absorber layer. The device is surface micromachined for thermal isolation and is self-supported by its contact metal legs, with no additional support structure. The design uses a vertical current flow arrangement suitable for a high resistivity a-GexSi1-xOy sensing layer and both sandwich and sandwich-gap configurations are demonstrated. Optimum polyimide sacrificial layer patterning for subsequent deposition of layers is described and optimum metal thickness for the required sheet resistance is studied. A planar surface for the deposited semiconductor layer is obtained by using a recessed base electrode structure. Finally optimum conditions for plasma releasing of the structure are described. © 2004 American Vacuum Society.