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.