Electrical characteristics of TaSixNy/SO2/Si structures by Fowler-Nordheim current analysis

In this letter, the Fowler-Nordheim tunneling in TaSixNy/SiO2/p-Si structures has been analyzed. The effective barrier height at the metal-oxide interface was extracted by Fowler-Nordheim current analysis. The barrier height was found to increase with increased annealing temperature. The barrier height was correlated with the extracted work function from capacitance-voltage analysis. This indicated that the work function of TaSixNy films changes under high temperature annealing from 4.2similar to4.3 eV after 400degreesC anneals to similar to4.8 eV after 900degreesC anneals. We believe that the mechanism that causes the work function to increase is the formation of a Ta-disilicide layer at the interface between the electrode and the dielectric. (C) 2002 American Institute of Physics.