Modeling of feature profile evolution in SiO₂ as functions of radial position and bias voltage under competition among charging, deposition, and etching in two-frequency capacitively coupled plasma

A feature profile evolution model of a trench in SiO₂ is developed in a two-frequency capacitively coupled plasma in CF ₄(5%)/Ar by considering two layers, a mixing layer and an overlaying polymer layer on the basis of a database of etching yield by extending our original physical computer-aided design (CAD) tool, VicAddress (vertically integrated computer-aided design for device processes). That is, the surface exposed to fluorocarbon plasma is considered under competition among the charging of electrons and ions, the deposition of radicals, and reactive etching by ions. The feature profile is also discussed in terms or the bias amplitude and the position on the wafer.