Stability and transport properties of microcrystalline Si1-xGex films

The crystallization evolution of boron and phosphorus doped amorphous Si1-x Gex films (5 x 10(17)-5 x 10(20) cm(-3)), deposited on SiO2/Si(001) substra tes by molecular beam in high vacuum at room temperature, were studied by X RD, TEM and SEM. The amorphous Si1-xGex films were fully crystallized at si milar to 600 degrees C. Up to 800 degrees C no morphology changes were obse rved. Between 800 and 950 degrees C, voids and hillocks: were gradually dev eloped in the films. which consequently collapsed. The Hall concentration a nd mobility were characterized in the Si1-xGex films, annealed between 600 and 800 degrees C. The mobility and conductivity of p-Si0.5Ge0.5 films at r oom temperature were found to be relative high: 60 cm(2)/V s and 2000 (Omeg a cm)(-1), respectively. (C) 1999 Elsevier Science S.A. All rights reserved .