Identification of Grown-In Efficient Nonradiative Recombination Centers in Molecular Beam Epitaxial Silicon

The vacancy-oxygen complex is identified as a dominant grown-in nonradiative center in both undoped and B-doped Si layers grown by molecular beam epitaxy at low temperatures. Such defects are introduced due to a low surface adatom mobility during low temperature growth and also due to ion bombardment as occurs, e.g., during potential-enhanced doping. When the deep level defects are abundant, residual shallow P donors also participate in efficient nonradiative recombination channels. The effects of postgrowth annealing and hydrogenation on these nonradiative defects are reported.