An Analytical Threshold Voltage Model for the Vertical Sidewall Mosfet with a Curved-Channel

Abstract

We present a new analytical model for surface potential and threshold voltage (Vth) for Single Gate Vertical MOSFET with curved channel. The influence of the corner effect in single gate vertical MOSFET is studied using two dimensional Poisson equation in both planar and spherical geometries. The electric field of the channel in single gate vertical MOSFET and impact on the threshold are studied. The relationship between the threshold voltage (Vth), channel length (L), channel concentration (NA), and the curved corner radius (r0) is given. The comparison with planar devices is provided. The characterization of single gate MOSFETs with curved-channel devices is attributed to the corner effect of the surface potential along the channel. The relationship between the minimum surface potential and the structure parameters is theoretically analyzed. Results confirm that the curved-channel of device gives contribution of the threshold voltage value and the Short Channel Effect (SCE)reduction of the device due to effects of the corner and gate oxide capacitance. These results show a good agreement with the numerical 2-D TCAD simulations. Keywords: Vertical MOSFET, Curved Channel, Analytical Model, Threshold Voltage, Short Channel Effect (SCE), Potential Barrier.