METHOD FOR PRODUCING A MONOCRYSTALLINE SI WAFER HAVING AN APPROXIMATELY POLYGONAL CROSS-SECTION AND CORRESPONDING MONOCRYSTALLINE SI WAFER

摘要

The invention relates to a method for producing a monocrystalline Si wafer having an approximately polygonal cross-section and the material quality of float zone-pulled Si crystals. The aim of the invention is to provide a method that is less complex than methods known from the art and that allows substantial material savings, crystals having a larger diameter and long pulling length. For this purpose, in an initial phase, at least one thin neck is vertically drawn downwards by known means from a suspended molten droplet before crystal rotation is reduced to a speed of between 0 and < 1 revs/min and an Si monocrystal having an approximately polygonal cross-section is vertically drown downwards in a growth phase. An inductor comprising means for shaping a current distribution is used to produce a temperature profile, its shape on the growth phase limit corresponding to the shape of the cross-section of the crystal rod to be pulled. The stationary growth of the crystal rod is terminated once the desired pulling length has been achieved and the crystal rod is cut to wafers having a polygonal cross-section. The invention also relates to monocrystalline Si wafers having an approximately polygonal cross-section and a polygonal striation pattern with an n-dimensional geometry.