The Impact of Chlorine on the Memory Characteristics of PEALD Si3N4 Charge Trap Layer-based MONOS Device

다국어 초록 (Multilingual Abstract)

In this paper, we conducted a study to establish an evaluation method for the charge trapping layer of MONOS capacitors, demonstrate the degradation mechanism, and propose process improvements for establishing excellent trapping layer characteristics based on the identified mechanism. The effective scaling down of MONOS devices requires developing an deposition strategy for the charge trapping layer utilizing PEALD and having an in-depth understanding of charge loss mechanisms and data retention features. To assess the impact of chlorine on the charge trapping layer, we analyzed the data retention and endurance characteristics in samples with varying amounts of chlorine introduced, comparing the experimental conditions. Quantitative results were extracted to investigate the correlation with the causes of Cl generation. The results were verified through electrical analysis methods such as the CV method and physical analysis methods including XPS, SIMS, ensuring their accuracy. Through this, we aimed to clarified the causes of charge loss, addressing the charge loss and mechanisms. This allowed us to explain the experimental data retention and endurance degradation. In conclusion, this study encompassed a comprehensive investigation, including theoretical research, as well as the fabrication of PEALD Si3N4 memory under various conditions, in order to understand and enhance the characteristics of 3D MONOS NAND flash memory.

목차 (Table of Contents)

• Abstract ⅷ
• Chapter1. Introduction · 1
• 1.1. NAND Flash overview and Trends 1
• 1.2. NAND Flash memory materials 4
• Chapter2. Background · 5
• 2.1. Program/Erase Operation 5
• 2.2. Scaling issue of 3D NAND Flash memory 10
• 2.3. The importance of thin conformal films 12
• 2.4. Plasma-Enhanced Atomic Layer Deposition (PEALD) 13
• 2.5. Silicon nitride Trap . 16
• Chapter3. Experiment 19
• 3.1. MONOS Capacitor structure flash memory manufacturing process
• 19
• 3.2. Measurements for Characteristic Analysis of Flash Memory of
• MONOS Capacitor . 22
• Chapter4. Results and Discussion · 24
• 4.1. TEM cross section image of the O/N/O layer 24
• 4.2. Cl generation mechanism and location in MONOS device . 25
• 4.3. Effect of Chlorine in O/N/O Layer on Memory Characteristics 31
• 4.4. Silicon oxynitride (SiOxNy) characteristic 41
• Chapter 5. Conclusion 45
• Reference 46