High speed spectroscopic ellipsometry technique for on-line monitoring in large area thin layer production

Non-destructive analyzing tools are needed at all stages of thin film process-development, especially photovoltaic (PV) development, and on production lines. In the case of thin films, layer thicknesses, micro-structure, composition, layer optical properties, and their uniformity are important parameters. Off-line point-by-point mapping can be effective for characterization of non-uniformities in full scale PV panels in developing labs but it is slow in the on-line mode. Last years [M. Fried et al, Thin Solid Films 519, 2730 (2011); 571, 345 (2014)], a new instrumentation was developed that provides a line image of spectroscopic ellipsometry (wl=350–1000 nm) data. Prototypes have built for 300–600–900 mm nominal width different structures (poly-Si/c-Si, ZnO/Mo, a-Si/Al, a-Si/glass) on rigid substrates. Thin layers (ZnO/a-Si:H;) on plastic foil substrates were also investigated in roll to roll operation, measurements and results of different structures are presented.