Vacuum ultraviolet to visible emission of some pure gases used for plasma processing

The vacuum ultraviolet (VUV) to near infrared (IR) emission (112 about lambda about 880 nm) from molecular gases (H2, O2) and molecular gas - noble gas mixtures (H2-Ar, O2-Ar) have been investigated with two separate spectrophotometric instruments. We report the influence of plasma parameters such as gas composition, pressure and microwave power upon the plasma emission. In the case of mixtures with noble gases, we selected a range of plasma parameters so as to obtain very intense VUV emissions, which can be useful for the photochemical treatment of polymer surfaces. The mechanisms involved are briefly discussed