| Scope and Method of Study. Described is an uncooled surface-micromachined thermoelectric (TE) infrared detector that features P-doped polysilicon/Nichrome (Cr20-Ni80) as the thermocouple material pair embedded in Parylene-N, which isolates the hot junction from the substrate. Simulation shows that the thermal conduction from the hot junction to the substrate through the TE wires is dominant (G_TE " G_parylene). By further reducing the size of the TE wires, G_TE could be decreased and hence, responsivity could be improved while parylene can provide the mechanical strength for the thin TE wires.;Findings and Conclusions: The fabricated detector features an umbrella-like absorber that permits high fill factors. The device area is 20 um * 20 um and the absorber area is about 19 um*19 um leading to a fill factor of as high as 90%. The absorber is an optical cavity composed of a three-layer stack.;At room temperature, the responsivity of 100 V/W 5 Hz and the response time of not greater than 26 ms were measured in vacuum when viewing a 500K blackbody with no concentrating optics. The D* is calculated to be cmHz0.5/W. |
