Modeling and numerical simulation of gate leakage current in strained-Si channel nMOSFETs with high-k gate dielectrics

The influence of strain on the gate leakage current has been investigated analytically in detail for strained-Si channel MOSFETs for a range of gate voltages and the gate insulator thicknesses. Our analysis relies on the determination of surface potential by solving the Poisson's equation using both the analytical and numerical approaches. The analytical model for the gate leakage current density has been proposed by considering strain dependent material and transport parameters and also band parameters. The different components of the gate leakage current densities such as the Fowler-Nordheim (F-N) and direct leakage current densities along with their sub components have been determined analytically for a wide range of strain values. Further the validity of our model has been confirmed by comparing our theoretical results for the gate leakage current density with the reported experimental data.