Deep-level transient spectroscopy of Si/Si1−x−yGexCy heterostructures

Deep-level transient spectroscopy was used to measure the activation energies 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 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 2×1015 cm−3. 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.