Electrical characterization of high-k based metal-insulator-semiconductor structures with negative resistance effect when using Al2O3 and nanolaminated films deposited on p-Si

In this work, the results of the electrical behavior of metal-insulator-semiconductor (MIS) structures using Al2O3, HfO2, and nanolaminated layers as gate insulators are reported. The MIS structures were deposited by atomic layer deposition on several Si substrates. The authors observed different conduction mechanisms for these high-k based MIS structures depending on the bias regime. Direct tunneling, Fowler-Nordheim, Poole-Frenkel emission, and a negative resistance region have been observed at different gate voltage values. The tunneling conduction of majority and minority carriers assisted by defects located at the Al2O3/HfO2 and Al2O3/metal interfaces can explain the negative resistance behavior observed in Al2O3 and nanolaminated samples. In addition to current-voltage (I-V) measurements, MIS structures were also electrically characterized using capacitance-voltage (C-V), deep level transient spectroscopy, conductance transients (G-t), and flat-band voltage transient (V-FB-t) techniques. (c) 2011 American Vacuum Society. [DOI: 10.1116/1.3521383]