Modeling of side wall passivation and ion saturation effects on etching profiles

A novel surface kinetics model is presented for simulating silicon and polysilicon profile evolution in plasma etching processes in which low energy ions and inhibitor forming species are used. It characterizes important phenomena such as the etching of the substrate material through a thin inhibitor layer and the saturation of the etching rate with the ion flux when the etching becomes neutral starved. The simulated profiles by using this model agree very well with experiments done in an inductively coupled high density plasma source as well as in a conventional parallel plate plasma source