Electrical Characterization of Extremely Thin (2.7 nm) Oxynitride and Oxide of Silicon Grown by N2O Plasma and Wet Oxidation at Low Temperatures: A Comparison

Extremely thin (2.7 nm) oxynitride and oxide of silicon are grown by N2O plasma and wet oxidation at low temperatures. These extremely thin dielectrics are characterized by fabricating metal oxide semiconductor (MOS) tunnel diodes, and studying their capacitance–voltage (C–V), and conductance–voltage (G–V) characteristics. The density of interface states (D it) for the as grown plasma oxynitride is high (2.1×1012 cm-2·eV-1) compared to that of wet oxide (3.8×1011 cm-2·eV-1), the density of fixed oxide charges (Q f) are comparable (∼5×1012 cm-2) in both the cases. It is shown that, post oxidation annealing (350°C) of the plasma oxynitride improves the quality of the Si/oxynitride interface.