Sources of errors in quasistatic capacitance-voltage determination of the interface state density distribution in the MOS system

Abstract

The sources of experimental error that can occur during the use of quasistatic capacitance-voltage measurements to determine the interfaces state density at the Si/SiO2 interface are discussed in terms of the fictitious interface state densities that they produce. It is shown that in the middle of the silicon energy bandgap this measurement technique can be used with confidence to measure interface state densities in the region of 1010 cm-2 eV-1. Closer to the band edges fictitious interface state densities of 1012 cm-2 eV-1 can be introduced by errors in the experimental data, and this limits the energy range over which the measurements are valid to approximately +or-0.3 eV around midgap.