Comprehensive reactor modelling and simulation of plasma etching of Si and SiO2 in SF6/argon

The analysis method of the dynamic mass balance has been employed to construct a comprehensive reactor model for plasma etching of silicon (Si) and silicon dioxide (SiO₂) with SF₆/Ar in this work. The model includes diffusion and convection of molecular fragments in a duct geometry, which could be estimated by using an effective diffusion length which takes surface reflection into account and increases as the surface reflection probability increases. Electron impact dissociation and ionisation reactions which depend on the electric field and gas density are the dominant sources of active species generation. Fluorine atom generation is also described by dissociative chemisorption. Fundamental plasma parameters such as electron density and electric field are estimated from impedance measurements in a designed experiments under the various operating conditions. Results presented in this paper show good agreement between the model predictions and the experimental data