Plasma analyser for plasma-assisted surface process diagnostics up to 100 mbar

Ion beam mass spectrometer (IBMS) has been developed for in situ, real-time monitoring of the ion composition of a plasma in the vicinity of the subst rate surface up to a pressure of 100 mbar. IBMS is a quadruple mass spectro meter-based plasma sampling system installed into a separately pumped small analysis chamber. The top part of the IBMS is specially designed to serve as the sample holder of the reactor chamber. A technique containing wet etc hing and laser treatment has been developed to form an orifice in various s ubstrates, that matches the pressure range to be studied. This orifice samp les the particles arriving onto the surface from the plasma, but is small e nough to maintain effusive gas flow into the analysis chamber. Behind the o rifice, a specially designed ion optics directs the ions coming from the pr ocess chamber into the QMS for mass and energy separation. Since particles are not altered after sampling, non-stable species can also be detected. Th e ion optics ensures that a high rate of ions reaches the QMS. The intensit y ratios in the spectra correspond to the concentration ratios of the ions arriving to the substrate surface. The QMS is also equipped with a conventi onal cross beam ion source allowing measurements of neutral species with po st-ionization. The performace of the system is demonstrated in a microwave plasma enhanced diamond CVD system. (C) 2000 Published by Elsevier Science Ltd.