Energy Levels Associated with Extended Defects in Plastically Deformed n-Type Silicon

Deep Level Transient Spectroscopy (DLTS) investigations of plastically deformed, n-type silicon have been performed. DLTS spectra revealed four lines usually found in deformed silicon but they were unusually dominated by a broadened level located at 0.40 eV from the conduction band edge. This trap resulted to be the most localized at the dislocations, while the other traps are probably related to point defects. The measured DLTS line widths have been simulated by the introduction of a broadening parameter δ, whose dependence on the dislocation density has been studied. Some hypotheses on the physical mechanisms responsible for the line broadening have been advanced. A tentative identification of the defects responsible for the deep levels observed has been performed.