A Compact Model to Predict Pillar-Edge-Roughness Effects on 3D Vertical Nanowire MOSFETs Using the Perturbation Method

摘要

In this paper, we present a compact model to predict the pillar-edge-roughness (PER) effects on 3D vertical nanowire MOSFETs using the perturbation method. An analytic solution to 3D Poisson's equation in the cylindrical coordinate with a perturbed boundary is obtained to describe the PER effects on the vertical channel potential. The induced variations of drain current, threshold voltage (V_(th)), and sub-threshold slope (SS) are calculated using the developed model. We also investigate the PER phase and frequency dependent behavior of the nanowire MOSFETs, and find that both phase and (angular) frequency of the PER function will significantly affect the device performance. Our model calculation results are compared with TCAD simulations and a good agreement between them is found. It is suggested that our metrology society needs to develop relevant measurement methodology to characterize the nanowire pillar-edge roughness at deep nanoscale.