Distributed microwave plasma sources: coupling modes and operation at high pressure for large area deposition
Résumé
The 2D and 3D distribution of a set of elementary plasma sources enables its use in large area
deposition and etching processes. Existing sources, working at 2.45 GHz, provide uniform plasma
conditions at low and very low pressures (up to a few Torr). A new challenge is to extend the
uniformity of the plasma at higher pressures, where the diffusion is limited by the scaling laws. We
will describe the transition between inductive and capacitive coupling modes as a function of
frequency (2.45 GHz, 915 MHZ and 352 MHz), gas pressure, source geometry and input power.
The understanding of the transition should allow the efficient design of new sources operating at
high gas pressure. Interest in this technology will be pointed out through some examples of
applications.