Mechanism for photo-assisted MOVPE nitrogen doping of ZnSe

Growth kinetics of pyrolytic and photoassisted MOVPE growth of ZnSe using dimethylzinc triethylamine adduct (DMZn.TEN) and ditertiarybutylselenium (DTBSe), diisopropylselenium (DIPSe) or diethylselenium (DESe) showed that low-temperature pyrolytic growth rates for all three Se precursors were similar. Photoassisted growth from DIPSe and DESe showed significant enhancement, but none was observed for growth from DTBSe. The hydrogen incorporation in the layers grown using DTBSe was two orders of magnitude higher than that for DESe which shows that high hydrogen incorporation can arise from the decomposition kinetics of the Se precursors. The proposed growth mechanism is based on surface radical reactions of H* with the adsorbed DESe. Photoassisted nitrogen doping with trimethylsilylazide (TMSiN) showed for the first time that nitrogen was being incorporated in the ZnSe layer at temperatures below 400 degrees C. (C) 1998 Elsevier Science B.V. All rights reserved.