Electronically induced defect creation at semiconductor/oxide interface revealed by time-dependent density functional theory

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/SiO 2 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•••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.

Programmable quantum emitter formation in silicon

“…Fs-laser pulses of varying intensity can steer these re-configuration processes and enable the programming, or selective writing and erasing of specific quantum emitters with properties optimized for selected applications, from quantum communications to quantum sensing. As a topic for future research, an in-depth understanding of these mechanisms will require simulations of non-adiabatic dynamics using methods such as time-dependent density functional theory, which has shown promise in the study of defect formation in the excited state 44 – 47 . We show how the choice of thermal annealing conditions with forming gas together with local fs laser pulse intensities allows for the selectively erasing or formation of specific quantum emitters.…”

New Insights Into Noise Characteristics of Hot Carrier Induced Defects in Polysilicon Emitter Bipolar Junction Transistors and SiGe HBTs

“…From a physical viewpoint of HCD, the reactiondiffusion theory has been a well-accepted framework for comprehensive understanding of the phenomena for a long period of time. Despite considerable progress in understanding and interpreting the electrical performance degradation behaviors has been achieved during the several past decades, but the exact underlying physics and atomic-level microscopic dynamics for the interface lattice defect formation are still missing [4]. It has been generally accepted that HCD involves two main mechanisms of bond breaking through incident carriers, either being very energetic or very numerous but less energetic [5,6].…”

Atomically precise AuxAg25−x nanoclusters with a modulated interstitial Au–Ag microenvironment for enhanced visible-light-driven photocatalytic hydrogen evolution

“…This overlapping PDOS of the d orbitals of the Ag and Au atoms suggests the formation of diffuse superatomic d-type orbitals, which could facilitate the transfer of hot electrons in space. 42,43…”