The effect of target density and its morphology on TiO2 thin films grown on Si(100) by PLD

Pure titanium dioxide (TiO2) thin films were deposited on single crystal Si(100) substrates by pulsed laser deposition (PLD). We investigated the effect of ambient gas (O-2 or Ar) and temperature on film quality. High quality TiO2 thin films were grown under low ambient pressures of oxygen and high substrate temperatures. The rutile phase is dominant under most experimental conditions. Only under very extreme conditions did we obtain thin films of the anatase phase. In relation to particulate problems, we investigated the effects of target morphology and target density on the sizes and the distribution densities of the particulates formed in the deposited thin film. Using a dense target and making laser shots to the point where the target surfaces begin to show a clear ripple pattern, we obtained nearly particulate-free thin film. It is desirable to monitor the morphology of both the target and the growing thin films to obtain the highest quality thin films. (C) 1999 Elsevier Science B.V. All rights reserved.