Study of metal strip insertion and its optimization in doping less TFET

Abstract

In this manuscript, a novel structure for dopingless tunnel field effect transistor (DL TFET) is introduced which comprises of metal strip (MS) in the oxide region near source/channel junction. Gate and drain work function engineering with hetero gate dielectric is used in this device which enhances the ON-state current, reduces the ambipolarity and also improves the RF performance. The increment in ON-state current with high subthreshold swing is achieved by the effect of MS. Steeper tunneling junction is achieved with the help of aforementioned modifications at the S/C junction. In this way, we increase the rate of tunneling at this interface and because of this, the threshold voltage of the proposed device reduces drastically. Further, study of ambipolarity suppression is done by using underlap of gate electrode near drain/channel (D/C) interface. Furthermore, temperature variation effect also incorporated in this manuscript, where study related to the threshold voltage and ON-state current is analysed by TCAD simulation. Moreover, most optimized MS length and work function are concluded in this paper for all simulations. Optimization for MS length and workfunction is analysed using TCAD simulation tool and shown in tabular form with one table showing effect of different work functions of MS on threshold voltage, ON-state current and SS, whereas another table shows the effect of MS length variations on RF parameters.