Although many ITO and other TCO coating processes are well established, increasing coating process speed, higher deposition rates and lower coating temperatures highly affect the layer uniformity, stoichiometry of the layer and crystallinity. All these parameters have a high impact on the conductivity and optical transpar-ency of the layer – the two main properties of TCO films.
Novel inline measurement technology is required to adapt to these challenges and to assure accurate and reli-able measurements of the electrical and optical properties even at high production speed. Therefore, non-contact sensors have been developed for monitoring sheet resistances and optical properties in non-contact. Especially the stable measurement of high ohmic samples is challenging and requires specific adaption of the sensor concept.
Examples of challenging inline measurements and non-destructive offline coating analysis are presented and discussed. A special focus is directed on the analysis, discussion and resolution of edge effect phenomena and other artifacts of the measurement. Furthermore the talk addresses pitfalls and best practice approaches for successful inline setups.