Growth, electrical and thermal properties of doped mono and polycrystalline SiGe-based quantum dot superlattices

SiGe materials present several advantages such as their compatibility with microelectronic techniques and non toxicity, but present a low figure-of-merit at room temperature. However it was shown theoretically that the figure of merit ZT could be highly increased by embedding nanoparticles in SiGe offering new potential applications. We report here the growth of different monocrystalline and polycrystalline SiGe-based quantum dot superlattices on Si (001) substrate. The QDSLs were grown using an industrial Reduced Pressure Chemical Vapor Deposition tool. In this work, SiGe spacer width as well as Ge dots sizes and densities have been controlled. The SiGe layers were heavily doped during the growth. Electrical and thermal properties of such structures have been measured and compared to standard SiGe thin films.