High-temperature thermoelectric measurement of B-Doped SiGe and Si thin films

Recent progress of thin-film type thermoelectric, TE, materials accelerates new microdevices working at room temperature to high temperature, and also requires the measurement techniques for the films. Modified four point pressure contact electrodes have been developed in this study, applied for the high temperature measurement of the resistivity and Seebeck coefficient of the boron-doped Si_0.8Ge_0.2 and Si thin films. The films were prepared by chemical vapor deposition method and then annealed at high temperature of 1050°C, and their Seebeck coefficients were investigated with two different measurement systems, block heating or air cooling electrodes, from 80 to 780°C. For this temperature range, the Seebeck coefficients of the boron-doped Si_0.8Ge_0.2 film and boron-doped Si film were 150̃350μV/K and 100̃ 250μV/K, respectively. The deviation of Seebeck coefficient was investigated with various measurement parameter, and the optimized temperature difference for the reliable measurement was found to be 2.2°C.