Deep-level transient spectroscopy of Si/SiGeC heterostructures

Deep-level transient spectroscopy was used to measure the activation energies of deep levels in n-type Si/SiGeC heterostructures grown by solid-source molecular-beam epitaxy. Four deep levels have been observed at various activation energies ranging from 231 to 405 meV below the conduction band. The largest deep-level concentration observed was in the deepest level and was found to be approximately 2×10cm. Although a large amount of nonsubstitutional C was present in the alloy layers (1-2 at.%), no deep levels were observed at any energy levels that, to the best of our knowledge, have been previously attributed to interstitial C. © 1998 American Institute of Physics.