High Rate and Low Temperature Deposition of TiO₂ Films by Sputtering

Abstract

  In reactive sputtering of titanium target in the oxide mode, oxygen atoms are selectively sputtered from the target surface, which leads to a significant reduction of deposition rate of TiO₂ films. Utilizing this phenomenon, we developed a sputtering type oxygen radical source. Combining this oxygen radical source with a titanium sputtering source which is operated in metal mode, we showed that a high rate deposition of TiO₂ films above 40 nm/min was achieved. In addition, it was confirmed that the crystal structure of the film (anatase and/or rutile) was easily controlled by the control of the amount of oxygen radicals and titanium atoms incident on the substrate surface. Low temperature deposition of crystallized TiO₂ films was also attempted by using this sputter-deposition method. As a result, it was found that deposition of a well crystallized TiO₂ films on unheated substrate could be realized by using crystallized TiO₂ seed layer and a proper ion bombardment.