Abstract: Two inches N-type sulfer-doped GaP single crystal was grown by high pressure LEC method,crystals diameter were controlled by floating coracle technique.The doping amount was calculated according to the theoretical formula, and the carrier concentration of the head, middle and tail of the sulfur-doped GaP single crystal were measured by the Vanderbilt method.The influence of the shape of the solid-liquid interface on the carrier distribution is analyzed.The flat solid-liquid interface has a more uniform carrier distribution in the crystal.The distribution of lateral and longitudinal carriers and their influencing factors on the coracle-controlled single crystal were analyzed.The longitudinal carrier distribution of the single crystal controlled by computer and the floating coracle is compared and discussed.It shows that the floating coracle control and process cause the change of the segregation coefficient and the compensation degree during the crystal growth, so that the longitudinal carrier concentration of the crystal first decreases and then rises.It is proposed that the single crystal longitudinal carrier uniformity can be improved by shifting crystal pulling.The influence of the weight of the coracle on the carrier distribution is discussed.The longitudinal carrier distribution is more uniform while using heavier coracle during GaP crystal growth.

Key words: high pressure LEC, coracle technique, Van der Pauw method, carrier concentration distribution