Atomic Level Insight into the Variation and Tunability of Band Alignment between Si and Amorphous SiO 2 /HfO 2

作者：Wenfeng Li, Ting‐Wei Liu, Zhengmei Yang, Lin‐Wang Wang, Yue‐Yang Liu · 发表于：Chinese Physics Letters · 年份：2024 · DOI：10.1088/0256-307x/42/1/017302 · 被引用次数：6 · 研究领域：Semiconductor materials and devices、Advancements in Semiconductor Devices and Circuit Design、Semiconductor materials and interfaces

Abstract The band alignment between silicon and high- k dielectrics, which is a key factor in device operation and reliability, still suffers from uncontrolled fluctuations and ambiguous understanding. In this study, by conducting atomic-level ab initio calculations on realistic Si/SiO 2 /HfO 2 stacks, we reveal the physical origin of band alignment fluctuations, i.e., the oxygen density-dependent interface and surface dipoles, and demonstrate that band offsets can be tuned without introducing other materials. This is instructive for reducing the gate tunneling current, alleviating device-to-device variation, and tuning the threshold voltage. Additionally, this study indicates that significant attention should be focused on model construction in emerging atomistic studies on semiconductor devices.