Low-voltage high-speed programming gate-all-around floating gate memory cell with tunnel barrier engineering

Abstract

Abstract The aim of this study is to investigate the memory performances of gate-all-around floating gate (GAA-FG) memory cell implementing engineered tunnel barrier concept of variable oxide thickness (VARIOT) of low- k /high- k for several high- k (i.e., Si 3 N 4 , Al 2 O 3 , HfO 2 , and ZrO 2 ) with low- k SiO 2 using three-dimensional (3D) simulator Silvaco ATLAS. The simulation work is conducted by initially determining the optimized thickness of low- k /high- k barrier-stacked and extracting their Fowler–Nordheim (FN) coefficients. Based on the optimized parameters the device performances of GAA-FG for fast program operation and data retention are assessed using benchmark set by 6 and 8 nm SiO 2 tunnel layer respectively. The programming speed has been improved and wide memory window with 30% increment from conventional SiO 2 has been obtained using SiO 2 /Al 2 O 3 tunnel layer due to its thin low- k dielectric thickness. Furthermore, given its high band edges only 1% of charge-loss is expected after 10 years of −3.6/3.6 V gate stress.