Automated instrumentation for nonequilibrium capacitance–voltage measurements at a semiconductor–electrolyte interface

Abstract

An apparatus for measuring nonequilibrium capacitance–voltage characteristics in semiconductor structures with electrolytic contacts is described. A pulse CV method was used in which a space-charge region in the deep-depletion mode was created via application of a bias-voltage pulse. Measuring the capacitance in a nonequilibrium mode makes it possible to avoid the formation of an inverse layer in an electrolyte–semiconductor system, whose presence leads to overestimation of the results of measuring the impurity concentration in narrow-band semiconductors. The possibility of applying this technique to measurements of the impurity concentration in weakly doped n-InAs is shown.