Influence of transverse current during In−O vapor deposition

The effect of electrical current flow parallel to the surface of growing In−O thin films was investigated. The films were produced by thermal vapor deposition of In−O powder in a vacuum of 1.3 mPa onto glass substrates at room temperature. Seven 15 × 1.5 mm² samples were deposited on each substrate through a mask, and silver paint electrodes were applied to the end of each sample. A potential difference of 0 to 110 V d.c. was applied to the central sample during deposition, while the remaining six films had no voltage applied. The current flowing during the deposition was monitored using a shunt. X-ray diffraction studies showed that all films were amorphous. It was observed that for the film grown with an applied voltage of 110 V, the radius of the first coordination sphere is 3% shorter than for the films grown without voltage. Optical microscopy and SEM showed an increased proclivity for a net-like microstructure to form with increasing applied voltage, with a typical cell dimension of 10 μm. The electrical conductivity of the In−O films grew rapidly with the applied voltage, reaching an improvement factor of 7 in comparison with films deposited without a transverse current.