Bulk Si1−xGex single- and poly-crystals: a new prospective material for electronics

Si1−xGex is a prospective material for electronics. This is mostly because Si1−xGex-based technology is close to silicon-based technology, which is advanced, widely applicable, and cheap. The majority of work on this material is devoted to Si1−xGex-based heteroepitaxy, and in particular to the Si1−xGex/Si system; few publications are devoted to bulk single-crystal. Here we focus on some interesting properties of bulk Si1−xGex solid solutions. First, under heat treatment and alpha- and beta-irradiation the efficiency of defect introduction decreases with the increase of Ge composition of the Si1−xGex single-crystal. This is because Ge atoms in a crystal lattice are annihilation centers for primary defects. Hence, this material is more resistant to temperature and radiation than silicon. Second, it is known that, since Z(Ge)≫Z(Si), the sensitivity of the material to irradiation should increase with the concentration of Ge. We show that Si1−xGex nuclear detectors have efficiency three times higher than silicon detectors. Finally, we note that one of the major problems in materials based on solid solutions is the composition uniformity. Our investigations on the influence of composition fluctuations on material properties have shown that the material has a sufficient uniformity at x<0.1. Such an alloy is a prospective material for electronics.