Analytical Modeling of an Ion-Implanted Silicon MESFET in Post-Anneal Condition

Abstract

Ion-implanted silicon MESFET modeling in post-anneal condition is carried out. Electrical parameters such as threshold voltage, drain-source current, and transconductance are studied. The channel charge is reduced with the increase in the diffusion coefficient of the implanted ions. Inclusion of diffusion effect due to annealing shows an increase in the threshold voltage under normally on condition and a reduction under normally off condition. At a fixed implant dose, anneal temperature may change the device from normally on to off and vice versa depending on the nature of dopant and anneal temperature. Drain-source current and transconductance also get reduced compared to the case where diffusion of the implanted ions due to annealing is not considered. © 1989 IEEE