EFFECT OF BUMPS ON THE WAFER ON ION DISTRIBUTION-FUNCTIONS IN HIGH-DENSITY ARGON AND ARGON-CHLORINE DISCHARGES

The presence of bumps on or near the wafer in plasma processing reacto rs can significantly affect plasma parameters. We have used a gridded energy analyzer to measure ion fluxes, energy distributions, and angul ar distributions near such bumps on a grounded electrode in an inducti vely coupled discharge in a Gaseous Electronics Conference Reference C ell. We find that the bumps affect the ion energy distributions only s lightly, lower the ion fluxes by more than a factor of 2 and dramatica lly alter the ion angular distributions. (C) 1997 American Institute o f Physics.