Molecular Dynamics (MD) Simulations and Thermochemistry of Reactive Ion Etching (RIE) of Silicon by Cl, C1_2, Br and Br_2 Cations

摘要

The difficulty in understanding plasma-surface interactions stems from a combination of physical complexity and an experimental environment that is difficult to interrogate. Because plasma-surface interactions have proven so very difficult to characterize experimentally, considerable effort has been expended to model RIE at an atomistic scale using as fundamental inputs the best available experimental data supplemented with ab initio electronic structure calculations of bond energies. From this rationale has come MD simulations of Si RIE by chlorine-containing plasmas based on atomistic models of interactions between plasma and surface, producing detailed yield, product distribution, chlorosilyl layer stoichiometry and surface roughness dependencies on impact energy and angle. These simulations have begun the process of understanding the relative contributions of physical collisions versus chemical reactions, sources of surface roughness in real devices, and feedback to feature and reactor scale models.