Improved interatomic potentials for silicon-fluorine and silicon-chlorine.

Area of Science:

• Materials Science
• Computational Chemistry
• Surface Science

Background:

• Accurate modeling of silicon-halogen interactions is crucial for semiconductor processing.
• Existing empirical potentials may not fully capture the complexities of these interactions.

Purpose of the Study:

• To develop and validate improved empirical interatomic potentials for silicon-fluorine (Si-F) and silicon-chlorine (Si-Cl) systems.
• To assess the performance of these potentials in simulating halogen etching of silicon surfaces.

Main Methods:

• Reparameterization of the Tersoff-Brenner potential form.
• Utilizing density-functional theory (DFT) cluster calculations for parameter fitting.
• Performing molecular-dynamics simulations of halogen atom exposure to silicon surfaces.

Main Results:

• Reparameterized potentials show excellent agreement with DFT calculations for halogenated silicon cluster energetics.
• Molecular dynamics simulations using the new potentials accurately reproduce experimental data on etch probability and halogen coverage.
• Simulations also align well with published etch product distributions.

Conclusions:

• The reparameterized Tersoff-Brenner potentials provide a reliable tool for simulating Si-F and Si-Cl interactions.
• These improved potentials enhance the understanding of halogen etching mechanisms on silicon surfaces.