Analytical Current-Voltage Model for Gate-All-Around Transistor with Poly-Crystalline Silicon Channel

Abstract

Poly-crystalline silicon channel transistors have been used as a display TFT for a long time and have recently been used in a 3D vertical NAND Flash which is a transistor with 2D plane NAND upright. In addition, multi-gate transistors such as FinFETs and a gate-all-around (GAA) structure has been used to suppress the short-channel effects for logic/analog and memory applications. Compact models for poly-crystalline silicon (poly-silicon) channel planar TFTs and single crystalline silicon channel GAA MOSFETs have been developed separately, however, there are few models consider these two physics at the same time. In this work, we derived new analytical current-voltage model for GAA transistor with poly-silicon channel by considering the cylindrical coordinates and the grain boundary effect. Based on the derived formula, the compact I-V model for various operating regions and threshold voltage was proposed for the first time. The proposed model was compared with the measured data and good agreements were observed.