Electronically induced defect creation at semiconductor/oxide interface revealed by time-dependent density functional theory
Author(s): Liu, YY (Liu, Yue-Yang); Wei, ZM (Wei, Zhongming); Meng, S (Meng, Sheng); Wang, RS (Wang, Runsheng); Jiang, XW (Jiang, Xiangwei); Huang, R (Huang, Ru); Li, SS (Li, Shu-Shen); Wang, LW (Wang, Lin-Wang)
Source: PHYSICAL REVIEW B Volume: 104 Issue: 11 Article Number: 115310 DOI: 10.1103/PhysRevB.104.115310 Published: SEP 30 2021
Abstract: Carrier induced defect creation at the semiconductor-oxide interface has been known as the origin of electronic device degradation for a long time, but how exactly the interface lattice can be damaged by carriers (especially low-energy ones) remains unclear. Here we carry out real-time time-dependent density functional theory simulations on concrete Si/SiO2 interfaces to study the interaction between excited electrons and interface bonds. We show that the normal interface Si-H bonds are generally resistant to electrons due to the delocalized nature and high energy level of the Si-H antibonding states, and due to the high-energy barrier to break the Si-H bond. However, if an additional hydrogen atom exists by attaching to a nearby oxygen atom (forming a "Si-H.-H-O" complex), the Si-H bond will be greatly weakened, including the reduction of energy barrier for bond breaking, and the lowering of the antibonding state energy level which favors electron injection. Together with the multiple vibrational excitation process, the corresponding Si-H bond can be broken much more easily. Thus we propose that the Si-H center dot center dot center dot H-O complex will be the center for defect creation and device degradation. We also explain why such a center might be relatively easy to form during the hydrogen annealing process.
Accession Number: WOS:000704417000004
ISSN: 2469-9950
eISSN: 2469-9969
Full Text: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.104.115310