Excimer laser reactive deposition of vanadium nitride thin films

We report on the deposition of thin vanadium nitride films by ablating vanadium targets in low-pressure N-2 atmosphere, and on their characterization. The targets were vanadium foils (purity 99.8%). 3 in, Si(1 1 1) wafers were used as substrates. Film characteristics (composition and crystalhne structure) were studied as a function of N-2 pressure (0.5-200 Pa), KrF laser fluence (4.5-19 J/cm(2)), substrate temperature (20-750 degreesC ) and target-to-substrate distance (30-70 min), Vanadium nitride is already formed at low N-2 ambient pressures (I Pa) and laser fluences (6 J/cm2) on substrates at room temperature. At the N-2 pressures of 1-10 Pa, the prevalent phase is VN. At higher pressures (100 Pa) and at relatively high laser fluences (16-19 J/ cm(2)), the dominant phase is V2N. The crystallinity of the films improves by increasing the substrate temperature. Well-crystallized films are obtained on substrates heated at 500 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.