Plasma potentials of 13.56-MHz rf argon glow discharges in a planar system

Abstract

The plasma potential of 13.56-MHz low-pressure argon glow discharges has been measured for various modes of applying the rf power in a geometrically asymmetric planar system. The plasma potential is determined from the energy distribution of positive ions incident on the grounded electrode. The voltages on the excitation electrode (target electrode) are carefully measured and the capacitive sheath approximation is used to relate these measured voltages to the measured plasma potential. This approximation is successful in most of the situations encountered in this low-pressure (20 mTorr) relatively low-power density regime. The effects of superimposing dc voltages on the excitation electrode are discussed.

Etching mechanism of niobium in coaxial Ar/Cl2 radio frequency plasma

“…The surfaces exposed to plasma are bombarded by the ions with energy gain in potential difference between bulk plasma and the surface. Time averaged plasma potential V p and the average ion energy ϵ ion in a collisionless sheath are related [6] as: ϵ ion = q (V p -V bias ) for inner electrode ϵ ion = q (V p ) for outer electrode The plasma potential can be changed by applying a positive DC bias to the inner electrode [6][7][8], which will change the sheath potential on the outer cylinder. The incident ion energy on the inner surface of the outer cylinder varies due to the change in sheath potential as illustrated in Fig.…”

Ion energy distribution measurements in rf and pulsed dc plasma discharges

“…The result is that the driven sheath is much thicker than the ground sheath. Figure 3(a) shows the equivalent circuit proposed by Kohler et al [27]. If the capacitive sheath approximation is assumed then the resistive components are negligible, i.e.…”

“…A simple circuit model of an asymmetric rf CCP discharge has been derived by Kohler et al [27]. This model is used here to obtain an expression for the rf component of the powered sheath potential.…”

“…In section 2 the experimental setups are described. In section 3 a simple circuit model of the rf CCP discharge, similar to that used by Kohler et al [26,27], is introduced and a number of analytical models of the IEDF in rf sheaths [28][29][30] are summarized. These models are combined with the measured IEDFs in the CCP reactor to estimate other important plasma parameters.…”

Efficient production of negative hydrogen ions in RF plasma by using a self-biased grid electrode

“…The area of the mesh grid is 25 cm 2 . Hydrogen plasma is generated by a 40 MHz power source in pressure range of 0.7 ~ 3.7 Pa. RF power RF is supplied to the electrode directly through a blocking capacitor (BC) in a range of 20 -80 W. As a result, self-bias voltage is induced on the electrode [22,23]. If necessary, Argon gas is used for obtaining basic parameters of plasma.…”