Hybrid functional calculation of electrical activity and complexing mechanism of Cu-related defects

TL;DR

This study uses hybrid functional calculations to analyze Cu-related defects in silicon, aiming to clarify defect configurations, formation energies, transition levels, and the Cu_PL line, enhancing understanding of Cu precipitation.

Contribution

It introduces a comprehensive computational analysis of Cu defects in silicon using HSE06 functional, proposing a new Cu_i4V model to explain experimental discrepancies.

Findings

Calculated defect configurations, formation energies, and transition levels.

Proposed a Cu_i4V model to explain the Cu_PL defect.

Insights into electrically active defects and Cu precipitation stages.

Abstract

Copper is a detrimental impurity in silicon with high diffusivity and a high tendency to precipitate. Interaction between Cu and other defects is essential for understanding the nature of Cu precipitation in silicon. Despite extensive experimental investigations of Cu-related defects in silicon, a comprehensive understanding remains elusive due to limitations of techniques in resolving defect configurations, as well as inconsistencies between theoretical and experimental results regarding transition levels. Moreover, the underlying formation mechanism of the well-known $\mathrm{Cu_{PL}}$ line is still unclear. In this work, configurations, formation energies, and transition levels of Cu-related defects in silicon are calculated using the HSE06 functional and finite-size correction. Defects involved in this study include $\mathrm{Cu_i}$, $\mathrm{Cu_{Si}}$, Cu-B, Cu-P, and Cu-H. A $\mathrm{Cu_{i4}V}$ model is proposed to explain the discrepancies between theory and experiment about $\mathrm{Cu_{PL}}$ defect. Our calculations may provide insight into the electrically active defects and the early states of Cu precipitation in silicon.