Modeling of polymer neck generation and its effects on the etch profile for oxide contact hole etching using Ar, CHF/sub 3/, and CF/sub 4/ gases

A simple model, which takes into account simultaneous ion-assisted etching and polymer deposition, is presented. The simulation and experiment of test structures show that polymer neck generation is the result of competition of ion assisted etching and polymer deposition along the the sidewall of the contact hole. As the polymer neck also plays as a self-shadowing mask, it determines the final etch profile of the contact hole.