Scanning ND:YAG laser system for industrially applicable processing in silicon solar cell manufacturing

In order to demonstrate different laser beam processes for solar cell manufacturing a state of the art high power scanning laser system has been installed at 'Fraunhofer ISE'. The high potential of laser beam techniques is mainly based on the contactless operation, making them suitable for fragile silicon wafers, and their in-line suitability. Besides, the laser process can be accurately controlled and hence, a perfect reproducibility is obtained even at high pulse repetition rates. Combined with the feed speed of the scanned laser beam of up to 10 m/s this allows short process times as necessary for industrial throughput. Laser beam applications that are presently under investigation are first the 'Laser-Fired Contacts' (called LFC), a technique for implementing the rear contact of dielectric passivated solar cells, and second 'Laser edge IS olation' (called LIS).