Structural defects and deep-level centers in 4H-SiC epilayers grown by sublimational epitaxy in vacuum

The parameters of deep-level centers in lightly doped 4H-SiC epilayers grow n by sublimational epitaxy and CVD were investigated. Two deep-level center s with activation energies E-c - 0.18 eV and E-c - 0.65 eV (Z1 center) were observed and tentatively identified with structural defects of the SiC cry stal lattice. The Z1 center concentration is shown to fall with decreasing uncompensated donor concentration N-d - N-a in the layers. For the same N-d - N-a, the Z1 center concentration is lower in layers with a higher disloc ation density. (C) 2000 MAIK "Nauka/Interperiodica".