Positioning of the precursor gas inlet in an atmospheric dielectric barrier reactor, and its effect on the quality of deposited TiOx thin film surface

Abstract

Thin film technology has become pervasive in many applications in recent years, but it remains difficult to select the best deposition technique. A further consideration is that, due to ecological demands, we are forced to search for environmentally benign methods. One such method might be the application of cold plasmas, and there has already been a rapid growth in studies of cold plasma techniques. Plasma technologies operating at atmospheric pressure have been attracting increasing attention. The easiest way to obtain low temperature plasma at atmospheric pressure seems to be through atmospheric dielectric barrier discharge (ADBD). We used the plasma enhanced chemical vapour deposition (PECVD) method applying atmospheric dielectric barrier discharge (ADBD) plasma for TiOx thin films deposition, employing titanium isopropoxide (TTIP) and oxygen as reactants, and argon as a working gas. ADBD was operated in filamentary mode. The films were deposited on glass. We studied the quality of the deposited TiOx thin film surface for various precursor gas inlet positions in the ADBD reactor. The best thin films quality was achieved when the precursor gases were brought close to the substrate surface directly through the inlet placed in one of the electrodes. High hydrophilicity of the samples was proved by contact angle tests (CA). The film morphology was tested by atomic force microscopy (AFM). The thickness of the thin films varied in the range of (80 ÷ 210)nm in dependence on the composition of the reactor atmosphere. XPS analyses indicate that composition of the films is more like the composition of TiOxCy.