A NEW 2-DIMENSIONAL MODEL FOR THE POTENTIAL DISTRIBUTION OF SHORT GATE-LENGTH MESFETS AND ITS APPLICATIONS

A new analytical technique for calculating the two-dimensional (2D) potential distribution of a MESFET device operated in the subthreshold region is proposed, in which the 2D Poisson's equation is solved by the Green's function technique. The potential and electric-field distributions of a non-self-aligned MESFET device are calculated exactly from different types of Green's function in different boundary regions, and the sidewall potential at the interface between these regions can be determined by the continuation of the electric field at the sidewall boundary. The remarkable feature of the proposed method is that the implanted doping profile in the active channel can be treated. Furthermore, a simplified technique is developed to derive a set of quasi-analytical models for the side-wall potential at both sides of the gate edge, the threshold voltage of short gate-length devices, and the drain-induced barrier lowering. Moreover, the developed quasi-analytical models are compared with the results of 2D numerical analysis and good agreements are obtained.