Development of dry processing techniques for CdZnTe surface passivation

A method for passivating the surface of Cd1-xZnxTe (CZT) x-ray and gamma ra y detectors using relatively simple dry processing techniques has been deve loped. Leakage currents were significantly reduced for several processing m ethods. CZT samples were exposed to an oxygen plasma and/or coated with a r eactively sputtered silicon nitride layer. Several parameters of the oxygen plasma step were found to be important for achieving enhanced surface resi stivity. SiNx has been previously characterized and was used because of its high dielectric quality and low deposition temperature. Reduction in leaka ge current after passivation by a factor of as much as twenty is demonstrat ed. Results are also presented which give a measure of the long-term stabil ity of the passivating layers.