Application of derived optical models for CIGS to an optical monitoring system

Optical models were developed for each of the stages of CIGS 3-stage deposition process using spectroscopic ellipsometry. The optical functions thus derived were used in an optical monitoring system installed in the pilot line at the PVMC's Halfmoon facility. This system consists of two fiber optic-based spectroscopic reflectometry units, set up in the sputtering line and the CIGS evaporation chamber. The use of regular fiber optics, instead of polarization-maintaining fiber optics, is sufficient for the purpose of process monitoring. In addition, the technique does not need to be used “in-situ”, but the measurements can be taken in-line, and are applicable to a variety of CIGS deposition techniques.