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 reactors can significantly affect plasma parameters. We have used a gridded energy analyzer to measure ion fluxes, energy distributions, and angular distributions near such bumps on a grounded electrode in an inductively coupled discharge in a Gaseous Electronics Conference Reference Cell. We find that the bumps affect the ion energy distributions only slightly, lower the ion fluxes by more than a factor of 2 and dramatically alter the ion angular distributions. (C) 1997 American Institute of Physics.