摘要 |
An apparatus includes a generator electrode, a discharge electrode that has an aperture, a dielectric structure between the generator electrode and the discharge electrode, and a charge spreading structure. The dielectric structure includes a charging region under the aperture. The charge spreading structure is on a surface of the charging region facing the aperture. The charge spreading structure is electrically disconnected from the generator electrode and the discharge electrode and spreads electrical charge carriers over underlying areas of the charging region. |