Thermal conductivity of symmetrically strained Si/Ge superlattices

This paper reports temperature-dependent thermal conductivity measurements in the cross-lane direction of symmetrically strained Si/Ge superlattices, and the effect of doping, period thickness and dislocations on the thermal conductivity reduction of Si/Ge superlattices. The Si/Ge superlattices are grown by molecular beam epitaxy on silicon and silicon-insulator substrates with a graded buffer layer. A differential 3 omega method is used to mea s ure the thermal conductivity of the buffer and the superlattices between 80 and 300 K. The thermal conductivity measurement is carried out in conjunct ion with X-ray and TEM sample characterization. The measured thermal conduc tivity values of the superlattices are lower than those of their equivalent composition bulk alloys. (C) 2000 Academic Press.