Optimization of threshold voltage nonvolatile flash memory using Taguchi method

This paper presents the optimization of threshold voltage Flash memory by varying four control factors i.e. thickness of tunnel oxide, bottom-oxide, nitride, and top-oxide. The Flash memory structure was simulated by using Athena and Atlas module of Silvaco software. By implementation of Taguchi method, these control factors are varied each with four levels and applied in L16 orthogonal array. Signal-to-noise (S/N) ratio and Pareto ANOVA analysis are then used to determine the optimal thickness for each control factors and the main factors that have an effect upon the threshold voltage. Finally a confirmation test was conducted to verify the optimal result is as predicted. Based on S/N ratio analysis, the optimal parameter combination obtained was A4B2C3D1. From the analysis of Pareto ANOVA, bottom oxide thickness was found as the most important parameter that affecting the threshold voltage of Flash memory.