Transport properties of polycrystalline SiGethin film for micro power generators
M. Takashiri1,2, G. Chen1
1 Mechanical EngineeringDepartment, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA
The transportproperties of polycrystalline SiGe thin films are studied for their potentialapplications in micro power generators. These thin films are deposited bylow-pressure chemical deposition (LPCVD). The microstructure of thepolycrystalline SiGe thin film is characterized by means of scanning electronmicroscopy and atomic force microscopy, and the Si/Ge ratio is identified byRutheford backscattering measurement. The doping is carried out by phosphorusand boron ion implantation, followed by annealing in a nitrogen ambient. Thethermoelectric transport properties of these thin films such as electricalresistively, Seebeck coefficient and thermal conductivity are measured alongthe film plane direction. The electrical resistivity is measured by 4-probemethod. The Seebeck coefficient is measured by applying temperature gradientacross the sample, and the resulting voltage is evaluated. The thermalconductivity is measured by a membrane method. Fabrication of SiGe micro power generators will also bereported.