A Physics Based Potential Model for Cylindrical Surrounding Gate MOSFETs with SiO2- Core Si-Shell Structure

X. Zhang, J. He, M. Chan, C. Du, Y. Ye, W. Zhao, W. Wu, W. Wang
PKU-HKUST ShenZhen-HongKong Institution, CN

Keywords: analytic model, core/shell, cylindrical surrounding gate MOSFETs (SRGFETs), Poisson–Boltzmann equation, Pao-Sah’s dual integral

Summary:

A physics based potential model for intrinsic long-channel cylindrical surrounding gate MOSFETs with SiO2 -core Si-Shell structure is presented in this paper. The accurate potential solution of Poisson’s equation in a cylindrical coordinate system is first derived under the gradual channel approximation. The drain-current equation based on drift-diffusion mechanism is obtained from Pao- Sah’s dual integral, which is expressed as a function of intermediate vabible. The model is continuous both from sub-threshold to strong inversion region and from the linear to the saturation region. The model has been extensively verified by 3D numerical simulations with a wide range of geometrical parameters.