Physics based analytical solution to undoped cylindrical surrounding-gate (SRG) MOSFETs

A physics based analytical solution to undoped cylindrical surrounding-gate (SRG) MOSFETs is derived in this paper by solving the Poisson-Boltzmann equation. The solution produces a closed form solution for the energy band bending. Based on the solution, the exact inversion charge density can be directly expressed as a function of the quasi-Fermi potential, gate voltage and device structure geometries. The accurate physics included in the analytical solution can be used to predict the performance of surrounding-gate MOSFETs under unconventional operation condition such as volume inversion effect due to silicon body diameter and structure dependent effective oxide thickness effects that are unique in a SRG MOSFET.