A model for multistep trap-assisted tunneling in thin high-k dielectrics -: art. no. 044107

A model for multistep trap-assisted tunneling (TAT) with strong dependence on the trap concentration is introduced. The current density J as a function of the applied voltage V for A1/chemical vapor deposition-Al2O3/SiO2/p-Si structures has been measured and fitted for 12 orders of magnitude in a temperature range from T=42 K to T=420 K. A trap concentration of N-T=1.3x10(19)/cm(3), an electron affinity of echi(el)=1.7 eV, and an effective electron mass of m(ox)=0.28 m(0) (m(0) is the electron rest mass) for the Al2O3 are used. A single set of parameters fits the leakage currents of all samples with different Al2O3 thicknesses at all temperatures. (C) 2005 American Institute of Physics.