Concise Analytical Threshold Voltage Model for Cylindrical Fully Depleted Surrounding-Gate Metal–Oxide–Semiconductor Field Effect Transistors

Abstract

On a basis of a quasi-2D potential analysis using the effective conducting path effect (ECPE), a concise analytical model for the threshold voltage in cylindrical fully depleted surrounding-gate (SG) metal–oxide–semiconductor field effect transistors (MOSFETs) is derived. With various depths of the effective conducting path, the minimum channel potential Φdeff,min induced by ECPE is used to develop the threshold voltage model. Besides the increased depth of the effective conducting path, a thin silicon body and a decreased oxide thickness can reduce threshold voltage roll-off simultaneously. It is also observed that the threshold voltage shift depends on the scaling factor. A large scaling factor is preferred to alleviate threshold voltage degradation. This paper not only provides a simple analytical model but also offers an efficient analysis of the threshold voltage of the short-channel cylindrical fully depleted SG MOSFETs.