The C_iC_s(Si_I)_n Defect in Silicon from a Density Functional Theory Perspective

Area of Science:

• Materials Science
• Solid State Physics
• Computational Materials Science

Background:

• Carbon is a significant defect in silicon (Si), impacting device performance by interacting with intrinsic point defects.
• In irradiated silicon, carbon defects can evolve into complex structures through interactions with self-interstitials.

Purpose of the Study:

• To elucidate the structure and energetics of carbon interstitial-carbon substitutional (CiCs) defects associated with silicon interstitials (SiIs) in irradiated silicon.
• To investigate the formation of larger CiCs(SiI)n complexes.

Main Methods:

• Utilizing density functional theory (DFT) to model and analyze defect structures.
• Calculating the binding energies of various defect configurations.

Main Results:

• The lowest energy configurations for CiCs(SiI) and CiCs(SiI)₂ defects were identified.
• Strong binding energies of -2.77 eV for CiCs(SiI) and -5.30 eV for CiCs(SiI)₂ were determined.

Conclusions:

• The study provides a detailed understanding of the structural and energetic properties of CiCs(SiI)n defects in silicon.
• These findings are crucial for predicting and mitigating the effects of carbon defects in irradiated silicon devices.