CHARACTERIZATION OF POLY-Si 70 % Ge 30 % FOR SURFACE MICROMACHINED THERMOPILES

The paper presents the material characterization methods and results of poly-Si70%Ge30% from the perspective of its thermoelectric applications. In view of this application, relevant properties, namely electrical resistivity, Seebeck coefficient, thermal conductivity and specific contact resistance, have been measured on both p-type and n-type poly-Si70%Ge30% prepared by Low Pressure Chemical Vapor Deposition (LPCVD) and Rapid Thermal Chemical Vapor Deposition (RTCVD). The overall thermoelectric properties, as characterized by the figure-of-merit, are reported. Further optimization can be approached by fine tuning the doping concentration and introducing an additional heavily doped thin layer on top of poly-Si70%Ge30%.