Fabrication of self-supporting polysilicon thermopile

A prototype self-supporting polysilicon-metal junction thermopile has been developed. In order to realize ideal higher thermal isolation, a thermopile without a membrane and having self-supporting structure is proposed. The hot and cold contacts in the proposed thermopile are reversible. The thermopile can be widely used for sensing elements of power generators, temperature sensors, radiation sensors, flow sensors, and so on. The thermocouple is composed of polysilicon and Au junction. The thermopile was fabricated by MICS (Micromachine Integrated Chip Service: three polysilicon layers structure). Outputs were measured as a function of distance between hot contact of the thermopile and the radiation source. In order to confirm performance of the thermopile, the output voltages were compared with theoretical values. The experimental results were in good agreement with the calculations.