Modeling source/drain lateral Gaussian doping profile of DG-MOSFET using Green’s function approach

Abstract

Present work has used Green’s function approach to derive a two-dimensional analytical model of the double gate (DG) MOSFET at the subthreshold regime of operation that considers the effect of inevitable source/drain (S/D) lateral Gaussian doping profile. The non-integrable Gaussian term has been converted into an integrable function for accurate Fourier coefficient calculation which is then used to determine the potential equations of all three regions. These equations are then utilized to formulate channel current (Isub), the threshold voltage (Vt) roll off and subthreshold slope (SS) of the device. The effects of lateral Gaussian profile at different gate length (L), and for devices with different combinations of oxide thickness (tox) and channel thickness (tsi) have been investigated. The results show that the S/D Gaussian doping profile has severe effects at scaled gate lengths, where gate electrostatic control is of paramount importance.