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.