Improving plasma density uniformities at VHF/UHF operating frequencies using a scalable, multi{\-}electrode, VHF/UHF plasma source

At VHF/UHF operating frequencies significant electrode voltage non-uniformities develop over even modestly sized electrodes leading to plasma density non-uniformities. This has frustrated the use of higher operating frequencies in larger area PECVD processes despite the potential for increased deposition rates and improved film quality. A scalable, multi-electrode, VHF/UHF plasma source is described that enables high frequency large area operation without plasma non-uniformities. Plasma uniformity data is presented over a series of powers, pressures and operating frequencies.