Production of a Periodic Plasma Structure by 400 kHz Capacitively Coupled Discharge

Two-dimensional periodic plasma structure of a density above 1×10¹⁰ cm^-3 is produced by a 400 kHz capacitively-coupled discharge, where the discharge is operated at ~10 Pascal argon. A living electrode, which is covered with a periodically hollowed insulator, is powered from a 400 kHz power supply through an impedance matching circuit. The net power is increased up to 450 W in the present experiments. The Langmuir probe diagnosis shows the formation of the spatially periodic modulation of the plasma density, where the densities at the peak and trough in the structure are 1.8×10¹⁰ cm^-3 and 1×10¹⁰ cm^-3 for 180 W rf power. The density ratio at the peak and trough positions in the structure is unchanged by the rf power.