The Effect of UV Irradiation on Antimony-Doped Tin Dioxide Thin Films Derived from Methacrylic Acid Modified Precursors

Abstract

In this paper, we report the effect of direct UV photopatterning on the compositional and morphological characteristics, and hence the conductivity, of antimony-doped tin dioxide thin films (55−70 nm) prepared using wet-deposition techniques. Direct UV photopatternability was achieved using methacrylic acid modified tin(IV) isopropoxide and antimony(III) isopropoxide as precursors. Spin-on deposited films were lithographically patterned using a UV light source (I line) with a contact mask. After developing, the structures were thermally converted to crystalline, conductive pure and Sb-doped tin oxides. The effect of the UV irradiation on the chemical composition, surface morphology, and crystal size of the fabricated films was investigated using XPS, AFM, and XRD, respectively. We found that the UV irradiation lowered the crystallization temperature, increased the crystal size in the pure or slightly doped samples, and resulted in a more homogeneous Sb dopant distribution. The increase in crystal size was found to correlate with a large increase in conductivity (up to 1500%).