Chemical Approaches to Organometallic Chemical Vapor Deposition of Wide Band-Gap II-VI Layers and Nanocrystal Composites

Organometallic chemical vapor deposition (OMCVD) of ZnTe was explored with tert-butyl(trifluoromethyl)tellurium, a novel precursor with a high vapor pressure and low decomposition temperature. Contamination of ZnTe films with ZnF2 crystallites was observed at growth temperatures below 400 'C, while almost pure ZnTe films were grown above 400 'C. Growth from bis(trifluoromethyl)tellurium yielded ZnTe films with low fluorine concentrations. The contamination mechanism was probed by molecular beam mass spectroscopy under OMCVD growth conditions. OMCVD of epitaxial ZnSe was explored with new organometallic selenium precursors. Particular emphasis was placed on the development of precursor chemistry for low temperature growth and p-type doping of ZnSe. Growth experiments with tert-butyl(allyl)selenium, in combination with (CH3)2ZnN(C2H5)3, yielded films with good surface morphologies and negligible carbon contamination (<5x10 1 7 atoms/cm3). Low temperatur