DETERMINATION OF DEEP LEVELS IN GOLD-DOPED POLYCRYSTALLINE SILICON

The deep acceptor levels associated with Au impurities have been investigated for single-crystal and polycrystalline silicon specimens with the use of electrical resistivity and Hall-coefficient measurements. The heat treatments related to possible grain-boundary segregation of Au impurities were performed for the polycrystalline specimens. Furthermore, in order to investigate the influence of lattice dislocations on the deep Au level, dislocation-free and dislocated single crystals were used and appropriate heat treatments were performed. It is shown that the activation energies for Au acceptor levels are strongly dependent on the presence of lattice imperfections such as grain boundaries and lattice dislocations in the Si crystal. A simple physical interpretation for these experimental findings is also given on the basis of tight-binding electronic theory.