Profiling of stress induced interface states in short channel MOSFETs using a composite charge pumping technique

Abstract The charge pumping phenomenon is studied and the limits of validity of different experimental alternatives are analysed, taking into consideration emission processes and short channel effects. As a result, a composite charge pumping technique, which can accurately give the energy distribution of interface state densities in short channel MOSFETs, is proposed. The experiment is based on the successive variation of the gate voltage pulse parameters (top and bottom levels, rise and fall times) at room and low temperatures. This method is then applied to study aging effects due to channel hot electron injection. The comparison of the experimental energy profile determined before and after electrical stress shows a global increase of interface states, which is more pronounced near the conduction band edge.