Elimination of systematic measurement inaccuracy in voltage-capacitance spectroscopy of semiconductor/insulator interface

摘要

An improved algorithm for measurements of quasi-static voltage-capacitance characteristics (VCC) of metal-insulator-semiconductor (MIS) structures is suggested. This algorithm includes the following stages: high-temperature depolarization of a MIS structure, its cooling at a constant depolarization voltage, measurement of the MIS current I(V{sub}g) upon the linearly time-swept (increasing or decreasing) gate potential, and averaging of the dependences I(V{sub}g) obtained in the modes of sweep rate β{sub}V> 0 andβ{sub}V < 0 (β{sub}V = 0). The method allows the systematic error of the VCC C(V{sub}g) measurement caused by the relaxation polarization of the insulator, leakage current, and shift of the electrometer zero to be eliminated. As a result, the accuracy and reliability of the determination of the interface state (IS) density N{sub}(ss)(E) are increased, and the energy range of the IS spectra is extended. To test the efficiency of the algorithm developed, it was used for determining the function N{sub}(ss)(E) in the system SiO{sub}2/(100)Si:P.