AVS 60th International Symposium and Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS-ThA

Paper PS-ThA12
Time-resolved Discharge Observation of an Argon Plasma Generated by Commercial Electronic Ballast for Remote Plasma Removal Process

Thursday, October 31, 2013, 5:40 pm, Room 104 C

Session: Low Damage Processing
Presenter: T. Cho, Applied Materials Inc.
Authors: T. Cho, Applied Materials Inc.
Y. Sen, Applied Materials Inc.
R. Bokka, Applied Materials Inc.
S. Park, Applied Materials Inc.
D. Lubomirsky, Applied Materials Inc.
S. Venkataraman, Applied Materials Inc.
Correspondent: Click to Email
Recently, a remote plasma reactor has been widely used to clean the wafer surface and especially for the removal of the silicon dioxide or silicon nitride over silicon with high selectivity in semiconductor manufacturing industry. In a remote plasma process, plasma is generated within a plasma reactor and delivers only radicals to the process chamber. Absence of plasma in the process region decreases the physical damages of the substrate by ion bombardment and the radicals created by the plasma results in chemical reactions at wafer surface. For a stable supply of radicals to process chamber, a plasma reactor has to be designed very carefully. In Applied Materials, Inc, the plasma reactor adopting a hollow cathode type electrode is being used as a remote plasma source. An argon plasma generated between the cone-shaped electrode powered by commercial electronic ballast and grounded plane electrode has been investigated. Since the electronic ballast has positive and negative cycle in a period, two different discharge modes of remote plasma reactor - the normal glow discharge mode and the hollow cathode discharge mode – have been observed. The hollow cathode discharge mode has wider operation window in gas pressure than the glow discharge one. The glow discharge started to be extinguished at higher pressure than 4.1 Torr and turned suddenly to another hollow cathode discharge mode in the holes on ground plate, while the hollow cathode discharge mode kept growing until 10 Torr. These results show that the stable operation window of the system could be defined 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.