Charge trapping in ultrathin Gd2O3 high-k dielectric

Charge trapping in ultrathin high-k Gd2O3 dielectric leading to appearance of hysteresis in C-V curves is studied by capacitance-voltage and current-voltage techniques. It was shown that the large leakage current at a negative gate voltage causes the generation of the positive charge in the dielectric layer, resulting in the respective shift of the C-V curve. The capture cross-section of the hole traps is around 2X10-20 cm2. The distribution of the interface states was measured by conductance technique showing the concentration up to 7.5X1012 eV-1 cm-2 near the valence band edge.