Influence of Voltage Polarity and Electrode Configuration on Discharge Formation in Radio-Frequency-Excited Microplasma Array

Abstract

Microplasma array technology has been applied to high-throughput processing of microstructures. However, the optimal conditions are not fully understood with respect to the operating parameters and array design. In the present work, radio-frequency discharges in microplasma arrays with coplanar electrodes were simulated using a two-dimensional fluid model. The applied voltage is a half-wave rectified voltage which has negative or positive polarity. The influence of voltage polarity and electrode configuration on the discharge formation was investigated in a Xe/Ne mixture. In the positive polarity mode, the high-density region of Xe ions was shifted from the electrode toward the center of the discharge space. On the other hand, the negative polarity promoted the localization of Xe excited species between the electrodes. The minimum sustaining voltage decreased with an increase in the electrode gap length between adjacent segments or an increase in the electrode width. An understanding of quantitative properties of these results should be useful for the discharge control of a typical microplasma array.