Thermal conductivity of Si/Ge superlattices

We report in this paper the thermal conductivity measurement of Si/Ge superlattices as a function of the temperature and the period thickness. The symmetrized Si/Ge superlattices are grown by MBE on Si substrates with a graded buffer layer. A comparative 3/spl omega/ method is used to measure the thermal conductivity of the buffer and the superlattices between 80K-300K. The thermal conductivity is carried out in conjunction with X-ray and TEM sample characterization. The measured thermal conductivity values are lower than that of their corresponding alloys and show a decreasing trend with increasing period thickness which are corroborated with the TEM characterization of the dislocation density.