
162 Crystal Growth and Evaluation of Silicon for VLSI and ULSI
of orientation is reported to be 12 min of arc for standard silicon crystal reections. Based
on these principles, commercial systems are available—one such unit is shown in Figure
5.7 [9]. A sample is prepared by using a water-based slurry of 500-mesh silica that was
subsequently etched with a freshly prepared 50% NaOH or KOH solution for 6–12
min. After cleaning the surface, high-intensity light is used to locate the correct crystal
orientations.
5.4 Ingot Slicing
Silicon is very hard, and special tools are needed to slice the ingot into smaller wafers.
Slicing is important, as ...