Gate leakage current simulation by Boltzmann transport equation and its dependence on the gate oxide thickness

As device dimensions shrink toward 0.1 μm, gate oxides are becoming so thin that MOSFET gate leakage current and oxide degradation are becoming limiting issues. We provide a more rigorous way to calculate gate leakage current. To achieve this we build upon the Spherical Harmonic Method of modeling, which deterministically solves the Boltzmann equation for an entire device. The method gives the distribution function and is 1000 times faster than MC. Once the distribution function is calculated, the tunneling probability is derived from the first principle WKB method. The barrier lowering effect is accounted for by the method of image charges. We calculate gate leakage current as a function of DC bias. The thermionic and tunneling components are compared at different DC bias points. The dependence of gate leakage current on gate oxide thickness is simulated