A new two-dimensional threshold voltage model for cylindrical, fully-depleted, surrounding-gate (SG) MOSFETs

摘要

Based on two-dimensional (2D) Poisson potential solution, a compact, analytical model for threshold voltage in cylindrical, fully-depleted, surrounding-gate (SG) MOSFETs is successfully derived. The minimum surface potential φ_(min, surface) is used to develop the threshold voltage model. Besides decreasing the characteristic factor, both the thin silicon body and gate oxide can reduce the threshold voltage roll-off simultaneously. It is also found that the threshold voltage shift is dependent on the scaling factor of λ_1L. The high scaling factor is preferred to alleviate threshold voltage degradation.