A new charge pumping method of measuring Si-SiO2 interface states

Abstract

A new method of measuring the density of band‐gap interface states at the Si‐SiO₂ interface has been developed. This method is based on a charge pumping phenomenon and can be performed on a metal‐oxide‐semiconductor transistor structure without the need for Shockley–Hall–Read statistics. Although the method requires knowledge of the gate voltage‐surface potential relationship, the measured density of states is not as sensitive to either errors or fluctuations in this relationship as other more common techniques. Other advantages of this new method are that it can measure the density of interface states over most of the band gap, it is relatively simple to implement, and has a resolution comparable to either the conductance or deep level transient capacitance techniques. Applying the new method to a transistor with a channel length of 50 μm and a width of 25 μm, the density of interface states has been measured to within 80 meV of the conduction band.