Abstract: In order to produce wafers suitable for fabrication of integrated circuits, an ingot of raw silicon must undergo a process which includes several steps. The ingot must be sawed into slices, the slices edge ground to remove roughness of the edges, lapped to remove as much saw damage as possible, stress relief etched to remove as small a damaged area as possible, then polished. Each of these steps requires removal of some of the material of the slice. The use of laser annealing reduces the amount of surface removed, as it repairs some surface damage, smoothes the surface, and when accomplished in a partial vacuum, improves the chemical composition of the material as related to electrical activity.

Abstract: A ribbon of semiconductor material is formed by supplying powdered semiconductor material at the bottom of a rectangular tube shaping guide while heating the semiconductor material in the region of the guide to produce a molten body of semiconductor material within the guide. The upper surface of the melt is contacted with a seed ribbon which is drawn upward while maintaining the supply of semiconductor material adjacent to the bottom of the guide.