Effect of electrode separation and material properties on plasma uniformity in dual frequency capacitively coupled plasma tools

Summary form only given. Dual frequency, capacitively coupled plasma (DF-CCP) tools are being developed for etching in microelectronics fabrication with the goal of separately controlling the production of etch precursors and ion energy delivered to the wafer. These tools typically use a high frequency (10s to 100s tens of MHz) to sustain the plasma and a low frequency (a few to 10 MHz) for ion acceleration. Due to finite wavelength effects, the radial distribution of power deposition and sheath potentials are functions of frequency, and so adjusting frequency is not a free parameter with respect to uniformity. In particular, there is evidence that varying reactor geometry coincident with changes in frequency can improve uniformity.
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