Ballistic Transport in Plasma Oxide Etching: A Realistic Universal Surface Reaction Model

We propose a universal surface reaction model that incorporates neutral and ion transport mechanisms through a steady-state passivation layer in high-aspect-ratio plasma oxide etching. This two-layer model effectively captures the concurrent deposition and etching characteristics by explicitly accounting for neutral diffusion and ion scattering transport processes. Detailed kinetic models for deposition and etching are developed to closely reflect the transport mechanisms in a steady-state passivation layer (SSPL), and their validity is supported by sensitivity analyses of key parameters against experimental data. Consequently, the proposed model provides a realistic description of plasma oxide etching behavior. Furthermore, by integrating this model with a well-established three-dimensional ballistic transport model in high-aspect-ratio (HAR) structures, we offer valuable insights into previously unexplored aspects of the HAR etching process.