Evaluation of Zn uniformity in CdZnTe substrates

The radial uniformity of Zn concentration in 4 in. CdZnTe crystals was impr oved by keeping uniform temperature distribution in the VGF furnace. The ma ximum temperature difference at the outside of crucible in radial direction was reduced to less than 1. The size of voids observed outside of the crys tals became small and the distribution has become well-uniformed. To evalua te the Zn uniformity, a new NIR (Near Infrared) instrument was developed us ing the diode array type spectrometer. The NIR spectra were analyzed by C.D . Maxey et al.'s(1) method. The Zn concentration in 4 in. CdZnTe substrates grown by modified furnace was more uniform than that of the conventional s ubstrates.