An Analytic Potential Based Velocity Saturated Drain Current, Charge and Capacitance Model for Short Channel Symmetric Double Gate MOSFETs

Abstract

This paper presents a velocity saturated and channel length modulated drain current, charge and capacitance model for a symmetric Double Gate (SDG) short channel MOSFET. The proposed drain current model partially evolves from an existing and well established analytical potential long channel DG MOSFET model and is further modified to be applicable for short channel devices. The projected model includes velocity saturation effect and short channel effects (SCEs) like channel length modulation (CLM) and threshold voltage shift. These effects are incorporated by considering pseudo-two-dimensional electrostatics at the drain end. The proposed work is derived from Pao-Sah integral without using charge sheet approximation. The drain current model captures the essential physics and signature of a modern velocity saturated short channel device and provides continuity in all regions of MOSFET operation. Solutions for charges and capacitances in the presence of velocity saturation and short channel effects are given explicitly. The results obtained in this work are as per the scale length theory applicable for a Double Gate (DG) MOSFET and hence may be used in compact modeling of nanoscale transistors.