プラズマと分光分析

V. 分光学的方法によるプラズマ診断

抄録

Plasma diagnostics by spectroscopic methods are reviewed with the emphasis on measurements of radical densities in reactive plasmas used for material processing. A brief introduction on the radiation equilibrium of plasmas will be given on the basis of a collisional-radiative model. Optical emission spectroscopy (OES) is an economical diagnostic method, but simple OES is not useful for estimating radical densities. An improved OES method is actinometry, which is widely used in reactive plasma experiments. Active spectroscopic methods such as absorption spectroscopy and laser-induced fluorescence are more reliable for measuring radical densities. Various types of absorption spectroscopy using various light sources will be introduced after a brief description of the fundamentals of optical absorption. The advantages of laser-induced fluorescence are the compatibility with imaging spectroscopy and the applicability to measurements of various quantities in plasmas.