A 2-D analytic model for the threshold-voltage of fully depleted short gate-length Si-SOI MESFETs

A two-zone Green´s function solution method is proposed to analytically model the potential distribution in the silicon film of fully depleted SOI MESFETs, in which the exact solution of 2-D Poisson´s equation is obtained by using the appropriate boundary conditions. From the derived analytic 2-D potential distribution, the bottom potential in the active silicon film is used to analyze the drain-induced barrier lowering effect and the threshold voltage is defined in terms of minimum channel potential barrier. The results of the developed analytic threshold-voltage model are compared with those of 2-D numerical simulation, and good agreements are obtained for the gate length down to 0.1 μm with wide ranges of structure parameters and bias conditions