Reduction of capacitive coupling in inductively coupled plasmas by solenoid coils on dielectric window

Abstract

Solenoid coils with grounded ends positioned on the dielectric window were proposed and numerically studied to reduce the capacitive coupling in conventional inductively coupled plasma (ICP) sources. The capacitive coupling between the plasma and the coils was subsequently suppressed, leading to a significant reduction of the window erosion. To understand the plasma characteristics and the advantages of this configuration, the discharges by the solenoid coil were modeled and compared with a conventional planar coil ICP discharge. The solenoid coil could generate a plasma with higher density than the planar coil under the same absorbed power. The ratio of inductive to capacitive heating power of the solenoid coil was more than one magnitude higher than that of the planar ICP source. The voltage drop on the dielectric window under the solenoid coil was significantly reduced, which was attributed to a potential shielding effect of the grounded end of the radio frequency coil.

Improvement of photoresist etching by impedance control of a bias electrode in an inductive discharge

“…Several studies have focused on increasing ion density by reducing capacitive coupling in the ICP; for example, connecting a balance capacitor to the antenna, reducing the antenna voltage to reduce capacitive coupling, increasing ion density [8,9], and controlling the ion density profile [10]. Another method is placing a Faraday shielding cage or plate between the antenna and the dielectric window to minimize the electrostatic field between the turns of the antenna [11][12][13]. This shielding effect may be limited in antennas with a few turns, such as the single-turn antenna [14].…”

Plasma and electrical characteristics depending on an antenna position in an inductively coupled plasma with a passive resonant antenna

“…For decades, several methods have been studied to improve the power transfer efficiency by adding a Faraday shield, applying a weak magnetic field [10][11][12], modifying an antenna (or dielectric) configuration [13][14][15][16], connecting a capacitor to the powered antenna [17][18][19], and adding ferromagnetic cores [20][21][22][23].…”

Influence of external parameters on RF inductive discharge plasma characteristics

“…However, even in the H-mode of RF-ID a parasitic capacitive channel inevitably forms due to the presence of parasitic capacitance between antenna and plasma. Numerically the influence of the capacitive component on the plasma properties of the inductive plasma reactors was considered in [15,39,40]. In [40] solenoid coils with grounded ends positioned on the dielectric window were proposed to reduce the capacitive coupling in conventional inductively coupled plasma sources.…”

“…Numerically the influence of the capacitive component on the plasma properties of the inductive plasma reactors was considered in [15,39,40]. In [40] solenoid coils with grounded ends positioned on the dielectric window were proposed to reduce the capacitive coupling in conventional inductively coupled plasma sources. The capacitive coupling between the plasma and the coils was subsequently suppressed, leading to a significant reduction of the window erosion.…”