Dry etching topography simulator with a new surface reaction model: MODERN

A new simulator for dry-etching has been developed to predict topological evolutions in geometries with submicrometer dimensions. Ever-changing adsorbed particle layers on the film surface being etched are modeled. Surface reaction rates are calculated by taking into account the interaction between incoming ion/radical fluxes and the adsorbed particle layer with finite surface coverage. Silicon-dioxide etching by hydrofluorocarbon gases is studied as an application. Unknown parameters of ion/radical fluxes, radical sticking coefficients and sputtering rate of deposited polymer film are partially determined a priori based on a profile fitting method between simulations and experiments by using an overhang test structure. Simulation results of surface profiles after etching show good match with experimental data for trench and hole configurations, where the competition between etching and deposition on the sidewall are reasonably well described.>