Radio frequency inductive discharge source design for large area processing

This paper examines planar radio frequency (RF) inductively coupled discharges for plasma processing of large area substrates. Concerns associated with increasing the size of spiral antennas are addressed through consideration of alternative antenna designs. A single straight antenna element is considered as a building block for rectangular antennas, and the interaction between neighboring straight antenna elements is addressed. It is shown that a discharge can be sustained with a single straight antenna element, and that in antenna designs that split the current through separate parallel paths, the path lengths must be equal for power to be evenly distributed. Further, we report evidence of destructive field interference (and associated poorer performance) for closely spaced parallel antenna elements with oppositely directed currents.