Effect of oxide tunneling on the measurement of MOS interface states

In principle, capacitance-voltage (C-V) and charge pumping techniques shoul d supply the same information on the energy distribution of interface state s, On the other hand, we have found from measurements taken on the same sam ples that the C-V method systematically gives a lower state density in the midgap region, with a steeper energy dependence. We show that the agreement is greatly improved by introducing in both extraction techniques the effec ts of carrier tunneling in slow oxide traps.