Neutralization by a corona discharge ionizer in nitrogen atmosphere

Electrostatic neutralization of multilayer-loading silicon wafers is demonstrated using a corona discharge ionizer in a nitrogen atmosphere, where AC and DC voltages are applied to two needle electrodes for generation of negative- and positive-charged particles, respectively. We observe that the surface potential of the silicon wafer decreases from ±1 kV to ±20 V within 3 seconds. The density profiles of the charged particles generated by the electrodes are experimentally and theoretically investigated in nitrogen and air atmospheres. Our results show the possibility that the negative-charged particles contributing to the electrostatic neutralization are electrons and negative ions in nitrogen and air atmospheres, respectively. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(3): 1–8, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21179