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 silicongermanium solid solutions in the concentration range from 0 to 25 at% germanium. Completely dislocation free crystals up to 8 at% germanium could be obtained. Since constitutional supercooling is the main reason preventing single crystalline growth, pyrometric temperature measurements have been performed to reveal the temperature slope at the interface and to determine the critical growth rate. The temperature gradient ΔT/Δz was found to increase with increasing germanium concentration.