Computational Modeling of Silicon–Hydrogen Bond Dissociation Using First-Principles Methods

Hydrogen plays a crucial role in modern silicon devices by passivating silicon dangling bonds and eliminating electrically active mid-gap states. However, during device operation, hydrogen dissociation can still occur and is considered a key factor in hot carrier degradation in silicon devices. Despite its importance, the exact mechanisms underlying this process remain poorly understood. In this work, we explore the detailed nature of Si-H bond dissociation. Our findings indicate that electron-stimulated desorption occurs when electrons temporarily occupy the antibonding states of Si-H bonds, leading to dissociation events with a measurable probability. This mechanism is supported by evidence from several experimental techniques, including scanning tunneling microscopy (STM) and low-energy electron collision studies. These results offer new insights into the fundamental processes contributing to hydrogen-related degradation in silicon devices, with potential implications for enhancing device reliability and performance.