AXIAL TEMPERATURE DISTRIBUTION IN SILICON-GERMANIUM GROWN BY THE RF-HEATED FLOAT-ZONE TECHNIQUE

The RF-heated float zone method has been used to study the segregation behaviour of silicon-germanium solid solutions in the concentration r ange from 0 to 25 at% germanium. Completely dislocation free crystals up to 8 at% germanium could be obtained. Since constitutional supercoo ling is the main reason preventing single crystalline growth, pyrometr ic temperature measurements have been performed to reveal the temperat ure slops at the interface and to determine the critical growth rate. The temperature gradient Delta T/Delta z was found to increase with in creasing germanium concentration.