Deep-level transient spectroscopy of Si/Si1-x-y GexCy heterostructures

Deep-level transient spectroscopy was used to measure the activation energi es of deep levels in n-type Si/Si1-x-yGexCy heterostructures grown by solid -source molecular-beam epitaxy. Four deep levels have been observed at vari ous activation energies ranging from 231 to 405 meV below the conduction ba nd. The largest deep-level concentration observed was in the deepest level and was found to be approximately 2 x 10(15) cm(-3). Although a large amoun t of nonsubstitutional C was present in the alloy layers (1-2 at. %), no de ep levels were observed at any energy levels that, to the best of our knowl edge, have been previously attributed to interstitial C. (C) 1998 American Institute of Physics. [S0003-6951(98)01631-3].