Dual plasma modes operation of hollow cathode electrode system for remote plasma removals for semiconductor manufacturing

Summary form only given. A remote plasma source for selective removal process in semiconductor device fabrication has been investigated. Plasma has been generated between the cone-shaped electrode powered by commercial electronic ballast and the grounded plane electrode with noble gases of argon, helium or a mixture gas of He+NF ₃ +NH ₃ for the pressure range from 1 Torr to 30 Torr. Sinusoidal voltage waveform and asymmetry electrode configuration alternate the glow discharge and the hollow cathode discharge modes in a cycle - two different discharge modes in a cycle. It is noted that the operating pressure windows of the hollow cathode discharge mode was wider than the glow discharge mode. The glow discharge started to extinguish at relatively higher pressure while the hollow cathode discharge mode kept growing. These results show that the stable operation window of the system could be limited by the glow discharge mode rather than the hollow cathode discharge mode and could be improved by optimizing the applied voltage waveform and electrode configuration.