IN-SITU HEATING AND CO-ANNEALING FOR LASER ANNEALED JUNCTION FORMATION

摘要

Improved methods of annealing a workpiece are disclosed. Lasers are used to both increase the temperature of the workpiece, and to laser melt anneal the workpiece. By utilizing lasers for both operations, the manufacturing complexity is reduced. Furthermore, laser melt anneal may provide better junctions and more well defined junction depths. By heating the workpiece either immediately before or after the laser melt anneal, the quality of the junction may be Improved. Shallow annealing may be accomplished and annealing may occur in the presence of a species to form a passivation layer, !f the workpiece is a solar cell, in-situ heating may improve open circuit voltage (Voc) or dark currents. Insitu heating of the substrate lowers the melting threshold of the substrate and also increases light absorption in the substrate. This reduces the power of the melt laser and hence reduces the residual damage.