Experimental study of hybrid capacitively/inductively coupled discharges

Summary form only given. Inductively coupled plasma (ICP) has been widely used in semiconductor industry, due to its perfect characteristics of reduced ion damage, independently controllable ion energy and high density plasmas.^{1, 2} In the actual industrial processes such as etching process, to control ion energy and plasma density, two independent RF power sources are conventionally applied to ICP, i.e., the power source through the coil and the bias source applied to a substrate electrode. And, the RF bias discharge is the same as capacitively coupled plasma (CCP). A Langmuir probe, Z-Scan and an intensified charge coupled device (ICCD) camera were employed to study the coupling effects in ICP with RF capacitively substrate biasing (CCP). Three coupling mechanisms were investigated: (i) At high ICP power (inductive discharge, ie. H mode), a decrease of plasma parameters (such as electron density, electron temperature and plasma emission intensity) with the increase of CCP power was observed. (ii) At low ICP power (capacitive discharge, ie. E mode), the sheath heating due to the substrate biasing affected the electron dynamics, and a bias-induced increase in plasma parameters was observed. (iii) At fixed CCP power, the plasma emission intensity, electron density and the electron energy distribution function were measured with the increase of ICP power.