Developments in the laser scribing of molybdenum layers.

Together with Manz, Plansee has been studying the influence of the coating parameters used during the sputtering of the molybdenum layer on laser scribing. The results show that the process pressure and target power have a great influence on quality.

Coating laboratory The laser scribing of sputtered molybdenum layers is an important step during the production of glass-backed CIGS solar modules. During this process, parts of the sputtered molybdenum layer are removed. The resulting structure is used for the electrical circuits within the module. However, what effect do the coating parameters used during the sputtering of the molybdenum layer have on the subsequent laser structure?

Up to now, this question has gone unanswered. Now, however, thanks to a collaborative research project conducted by Manz – a leading manufacturer of laser scribing systems – and Plansee, the answer is becoming clearer. The results obtained by our developers show that the coating parameters used during the sputtering of the molybdenum layers have a significant impact on the quality of the structured areas. The crucial factors are the process pressure and target power since these modify the mechanical stresses in the molybdenum layer and therefore influence the quality of the scribing. Another result of the research is that compared to layers in areas subject to compressive stress, layers subject to tensile stress require significantly less laser fluence for full ablation to occur.

As a leading manufacturer of sputtering targets for thin-film solar cells, we are in constant contact with our customers and leading research institutes. Thanks to the many research projects it has been involved in and the work of its in-house laboratory, Plansee has been able to develop new coating materials and optimize its coating processes. Our products offer outstanding material purity and density coupled with a uniform microstructure – important prerequisites for the manufacture of flawless thin films.