Recent developments in the pyrolytic and photolytic deposition of (Cd,Hg)Te and related II–VI materials

Recent results for the pyrolytic MOVPE of cadmium mercury telluride (CMT) and related compounds are reported. In pyrolytic MOVPE the role of “new” tellurium precursors and their potential for developing low temperature epitaxy is reviewed. Very high purity CMT layers which show classic p-type behaviour are discussed. The limitations of the cool down process in giving rise to complex (“anomalous”) Hall measurements are analysed. The interdiffused multilayer process (IMP) has been used to grow very uniform CMT (Δx = 0.004 over 2.5 cm) using iPr2Te at 350°C. Growth on GaAs substrates has been shown to give some of the best crystallographic quality CMT layers yet reported. MOVPE CMT has been fabricated into infrared detectors showing state-of-the-art performance in the 8–14 μm band. Developments in photolytic growth of CMT and particularly CdTe are reported, in particular the use of laser photo-induced epitaxy, to achieve local area patterning is demonstrated.