THE DYNAMIC GRADIENT FREEZE GROWTH OF (TI+ZN) DOPED SEMI-INSULATING INP

High quality single crystals of semi-insulating InP were grown by the electrodynamic gradient freeze technique. The material is co-doped with the shallow acceptor zinc and the deep donor titanium. Resistivities in the 105-106 Ω cm range were measured with corresponding mobilities of 2500 cm2 V-1s-1. Variable temperature Hall measurements resulted in an activation energy 0.61 ± 0.03 eV below the conduction band. The dislocation density is less than 500 cm-2 and is the lowest ever reported for comparably sized semi-insulating InP bulk crystals. Precipitates containing titanium and phosphorus were found when the titatium concentration exceeded 3 × 1016 cm-3. A distribution coefficient of 4 × 10-4 was measured for titanium in InP. The precipitates have been identified for the first time as hexagonal TiP using X-ray powder diffraction. © 1990.