Improved electrical characteristics and reliability of amorphous InGaZnO metal-insulator-semiconductor capacitor with high κ HfOxNy gate dielectric

High kappa HfO(x)N(y) film was deposited on amorphous InGaZnO (a-IGZO) by radio-frequency reactive sputtering using an HfO(2) target in nitrogen plus argon ambience, the electrical characteristics and reliability of a-IGZO metal-insulator-semiconductor (MIS) capacitors were investigated. Experimental results indicate that the nitrogen incorporation into HfO(2) can produce a strong nitride interfacial barrier layer, thus lead to reducing the interface state density, suppressing the hysteresis voltage, and decreasing the gate-leakage current. Improved performance has been achieved for HfO(x)N(y) gate dielectric a-IGZO MIS capacitors, with a interface state density of 5.1 x 10(11) eV(-1) cm(-2), a gate-leakage current density of 3.9 x 10(-5) A/cm(2) at V(fp), + 1 V. an equivalent permittivity of 24, and a hysteresis voltage of 105 mV. Moreover, the enhanced reliability of Al/HfO(x)N(y)/a-IGZO MIS capacitor is observed with a small degradation of electrical characteristics after a high field stressing at 10 MV/cm for 3600 s. (C) 2010 Elsevier Ltd. All rights reserved.