MOVPE OF II-VI MATERIALS

The development of II-VI MOVPE is reviewed, contrasting the narrow ban dgap materials with the wide bandgap. Common issues are the need to gr ow the layers at lower temperatures than their III-V cousins in order to avoid point defects. This means that II-VI MOVPE occurs in a surfac e kinetic regime for precursor decomposition and has stimulated a lot of research on alternative precursors. The narrow bandgap II-VI grower s have settled on dimethyl cadmium (DMCd) combined with diisopropyl te lluride (DIPTe) and a liquid Hg source but wide bandgap growers are sp lit between pyrolytic and photo-assisted growth. Recent progress in p- type doping has enabled the demonstration of some new devices, includi ng two colour infrared detectors and the first MOVPE grown green emitt ing laser structure. The common theme appears to be hydrogen passivati on of the Group V dopant and some novel precursor solutions to this pr oblem are discussed.