RADIO-FREQUENCY INDUCTIVE DISCHARGE SOURCE DESIGN FOR LARGE-AREA PROCESSING

This paper examines planar radio frequency (RF) inductively coupled di scharges for plasma processing of large area substrates. Concerns asso ciated with increasing the size of spiral antennas are addressed throu gh consideration of alternative antenna designs. A single straight ant enna element is considered as a building block for rectangular antenna s, and the interaction between neighboring straight antenna elements i s addressed. It is shown that a discharge can be sustained with a sing le straight antenna element, and that in antenna designs that split th e current through separate parallel paths, the path lengths must be eq ual for power to be evenly distributed. Further, we report evidence of destructive field interference (and associated poorer performance) fo r closely spaced parallel antenna elements with oppositely directed cu rrents.