Control of ion energy and angular distributions using voltage waveform

Summary form only given. A number of plasma-aided microelectronics manufacturing processes sensitively depend on the ion characteristics at the substrate, in particular the ion energy (IEDF) and angular (IADF) distribution functions. The outcome of these processes can be much more precisely controlled if one has direct control over the IEDFs and IADFs. Past studies have explored the influence of rf bias voltage amplitude and frequency, inductive power deposition and gas pressure on the ion characteristics at the substrate. The factor that influences the ion dynamics most is however the time dependent sheath voltage and, as demonstrated in this paper, sheath voltage can be accurately controlled using the rf bias voltage waveform. In this paper, we computationally examine the influence of the rf bias voltage waveform on the IEDFs and IADFs at the substrate in an inductively coupled plasma (ICP) reactor. This study has been conducted using a coupled set of the Hybrid Plasma Equipment Model (HPEM) and a circuit model, and the Plasma Chemistry Monte Carlo Simulation (PCMCS). The HPEM is a 2-dimensional hybrid simulation of the plasma dynamics. The circuit model uses HPEM results in conjunction with the Riley´s sheath model to estimate de bias, sheath voltages and electrode currents. Once steady-state plasma and circuit quantities have been computed, a Monte Carlo simulation (PCMCS) is used to determine the IEDFs and IADFs at the substrate.