We have developed a semiempirical feature scale model of Si etching in SF6 plasma, which incorporates the addition of small amounts of O in the discharge coming from the etching of the oxide mask and quartz window. The degrees of freedom in the model are reduced by using information from plasma diagnostics and previously published data to estimate the ion flux, the ion energy and angle distributions, and the relative F and O fluxes. Experimentally inaccessible parameters such as the F sticking coefficient, chemical etch rate constant, and the ion-enhanced etch yield are determined by matching simulated feature profiles with those obtained from carefully designed etching experiments. Excellent agreement between experiments and simulations is obtained.
|Original language||English (US)|
|Number of pages||15|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|State||Published - Jan 2005|
Bibliographical noteFunding Information:
This work was funded by the University of California Discovery Program Grants (SM01-10079 and ele03-10156) and by Lam Research Corporation. The authors wish to thank the valuable technical help of Ricky March, Denise Gavello, Stanley Siu, and Norm Williams of Lam Research Corporation.