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

2 Research Division, Komatsu Ltd., 1200 Manda, Hiratsuka, Kanagawa254-8567, Japan


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.