3. Classification of equipment and pulling techniques by µ-PD

The µ-PD process is based on pulling single-crystal fibers or formats of controlled geometries down through a crucible using a well-dimensioned capillary to generate the desired crystal geometry.

Today, there are various types of micro-pulling-down equipment for single-crystal fibers. There are, for example, pulling machines using double-walled, water-cooled metal chambers with a diameter of one meter (figures 5 a and 5 b), or smaller pulling machines using quartz tubes (figure 6 ).