POSITIVE AND NEGATIVE LOW-ENERGY ION-BEAM DEPOSITION APPARATUS AND APPLICATIONS

A dual ion beam deposition apparatus was newly developed. The machine consists of a positive ion beam line, a negative ion beam line and an ultra-high vacuum deposition chamber. The machine can generate mass-an alyzed very low energy ion beams with positive and negative charges at the same time. Ion energy range covers 10 eV to 20 keV. It is possibl e to deposit these ions directly on a substrate not only simultaneousl y but also alternatively or independently. The machine has a wide poss ibility to fabricate such as ultra-pure materials or nontraditional ma terials. The machine is also useful to study fundamental processes of ion beam deposition and/or ion solid surface interactions. Using the n ew apparatus, isotopically pure carbon nitride (CxNy) films were fabri cated by simultaneous deposition of C- and N+ ions. The ion energy was varied from 50 to 400 eV. The films were analyzed by Rutherford backs cattering spectroscopy (RBS), Fourier transform infrared spectroscopy (FTIR) and Raman scattering. It was found that the maximum composition ratio (N/C) was about 0.9, the film structure was amorphous carbon-li ke and the amount of C-N triple bonds tended to decrease with decreasi ng nitrogen ion energy. (C) 1998 Elsevier Science S.A. All rights rese rved.