Beam shaping - the key to high throughput selective emitter laser processing with a single laser system

The fabrication of selective emitters by laser processing has attracted the interest of researchers in recent years. However, narrow foci of Gaussian laser beams limit the throughput and feature an inhomogeneous intensity distribution on the wafer. The use of beam shaping can eliminate this setback. A single laser system delivering <;70 Watt to the wafer is already sufficient to achieve short processing times per wafer. The feasibility of a laser system for a selective laser doping process from PSG is investigated and the potential of eligible beam shaping is assessed. Adequate sheet resistances with a good homogeneity and process stability can be achieved, with minor impact to random pyramid surfaces and no measureable degradation of the material. A diffractive optical element splitting one laser into 10 spots of equal intensity is evaluated and fast processing times are achieved.