Semiconductor Physics, Quantum Electronics & Optoelectronics. 2008. V. 11, N 4. P. 324-328.
Novel hysteresis effect in ultrathin epitaxial Gd2O3 high-k dielectric
1V. E. Lashkaryov Institute of Semiconductor Physics, NASU, 03028 Kyiv, Ukraine
Abstract. Charge trapping in ultrathin high-k Gd 2 O 3 dielectric leading to appearance of hysteresis in C–V curves is studied by capacitance-voltage, conductance-frequency and current-voltage techniques at different temperatures. It was shown that the large leakage current at a negative gate voltage causes the reversible trapping of the positive charge in the dielectric layer, without electrical degradation of the dielectric and dielectric- semiconductor interface. The capture cross-sections of the hole traps are around 10 –18 and 2 × 10 –20 cm 2 . The respective shift of the C–V curve correlates with a “plateau” at the capacitance corresponding to weak accumulation at the silicon interface. Keywords: high-k dielectric, dielectric-semiconductor interface.
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