ITO targets by SPS for TCO thin films deposition

Transparent conductive oxides (TCOs) have attracted great attention in a wide variety of applications where high transmittance in visible range and low resistivity are necessary, such as thin film photovoltaics, semiconductors, optics, decorative coatings and wear and corrosion protection... Currently TC market is by far dominated by a single material, tin-doped indium oxide (ITO), with a share of 87.2% in 2012. The industrial technology mainly used for the application of ITO layers is Magnetron Sputtering. Sputtering ITO presents a serious industrial problem due to the formation of nodules on the surface of sputtered targets, which leads to poor quality and high defect density ITO films. There is a lack of understanding as to what results in the growth of nodules, which process parameters are important, and how to tackle this problem. But it is thought that the ceramic target used for sputtering is one of the key aspects. The ceramic targets should be of high purity with a uniform microcrystalline structure and should possess high density and high electrical conductivity. This project aims at producing high quality ITO target by SPS, considering ceramic target composition (the ratio of In2O3:SnO2), the quality starting materials -with respect to purity, morphology and sinterability-, manufacturing routes and sintering process. The machine involved in this project is the biggest SPS system manufactured so far, being able to produce targets with up to 400 mm diameter. The performance of new ITO targets will be measured and evaluated by two factors: - The characterization of ITO film properties (optical and electrical) deposited using different ITO targets - The increase of ITO production rates due to new targets usage. Reduction of undesired down time and target cleaning. Lab-scale (circular target: 76mm diameter) and industrial-scale (rectangular target: 550x133mm) sputtering systems will be used for new ITO target validation.