METHOD FOR CONTROLLING RADIAL DISTRIBUTION OF PLASMA ION DENSITY AND ION ENERGY AT A WORKPIECE SURFACE BY MULTI-FREQUENCY RF IMPEDANCE TUNING

摘要

The method of performing physical vapor deposition on a workpiece includes performing at least one of the following: (a) increasing ion density over a workpiece center while decreasing ion density over a workpiece edge by decreasing impedance to ground at a target source power frequency f_s through a bias multi-frequency impedance controller relative to the impedance to ground at the source power frequency f_s through the side wall; or (b) decreasing ion density over the workpiece center while increasing ion density over the workpiece edge by increasing the impedance to ground at f_s through the bias multi-frequency impedance controller relative to the impedance to ground at f_s through the side wall.