Novel surface wave technique for moderate-pressure plasma measurements

Abstract

Most in situ plasma diagnostics are only reliable for low-pressure systems, e.g., systems where the collision frequency, νen, is small compared to the plasma frequency, ωpe. In this article, we describe a novel diagnostic technique for simultaneous measurement of the plasma density, ne; electron temperature, Te; and νen in systems in which νen approaches ωpe. We illustrate the operational setup of our probe system along with an analytical framework for ascertaining ne, Te, and νen. Furthermore, we show experimental results from argon capacitively coupled plasma operating in the 0.5–1 Torr pressure range.