The importance of studying the homogeneity of large area coating processes is shown. A method consisting of rather simple optical measurements & a newly developed connected fit algorithm was introduced. Using the example of a reactive sputter process for ITO-deposition, it was shown how the distribution of important physical properties of the film could be extracted. Several shortcomings of a particular sputter arrangement could be identified; essential information for further improvements of the used sputter equipment. In the course of the analysis, the sputtering of ITO on industrial style equipment was studied. It followed that gradients of oxygen partial pressure as caused by improper design of oxygen inlets & pump outlets are a main reason for inferior film resistivities. The presented algorithm can be readily adapted to similar problems.
