Anomalous temperature dependence of deep-level-transient-spectroscopy peak amplitude

The frequently observed variation of the deep-level-transient-spectroscopy (DLTS) peak amplitude with emission rate is often attributed to peculiar characteristics of the investigated traps: (i) broadening of the trap activation energy resulting in nonexponential capacitance transients, (ii) ampheteric behavior of the deep level, and (iii) temperature dependence of the capture cross section. Otherwise it could be attributed to factors related to the technique itself such as contribution of the lambda volume and effect of the leakage current. In this work we demonstrate that the DLTS peak amplitude variation effect is sometime due to the presence of a Coulombic repulsive barrier associated with the defect investigated.