New application for isothermal capacitance transient spectroscopy: Identification of tunneling in semiconductor-insulator interfaces

Abstract

The GaAs-insulator interface is characterized by deep level transient spectroscopy (DLTS) and isothermal capacitance transient spectroscopy (ICTS). It is demonstrated that while DLTS can only detect transients with temperature-dependent emission rates, ICTS can detect temperature-independent phenomena as well. The GaAs-insulator interface is characterized by two electron traps, with activation energies 0.67 and 0.23 eV, respectively, and a tunneling component that is detected only by ICTS. This tunneling component, which dominates the ICTS spectrum at 80 K<T< 180 K and is characterized by a field-induced barrier reduction given by ΔEE=1.4×10−3q√E, is attributed to pure tunneling.