Stability and transport properties of microcrystalline Si_(1-x)Ge_x films

摘要

The crystallization evolution of boron and phosphorus doped amorphous Si_(1-x)Ge_x films (5 * 10~(17)-5 * 10~(20) cm~(-3)), deposited on SiO_2/Si(001) substrates by molecular beam in high vacuum at room temperature, were studied by XRD, TEM and SEM. The amorphous Si_(1-x)Ge_x films were fully crystallized at ～600 °C. Up to 800 °C no morphology changes were observed. Between 800 and 950 °C, voids and hillocks were gradually developed in the films, which consequently collapsed. The Hall concentration and mobility were characterized in the Si_(1-x)Ge_x films, annealed between 600 and 800 °C. The mobility and conductivity of p-Si_(0.5)Ge_(0.5) films at room temperature were found to be relative high: 60 cm~2/V s and 2000 (Ω cm)~(-1), respectively.