MECHANISM FOR PHOTO-ASSISTED MOVPE NITROGEN DOPING OF ZNSE

Growth kinetics of pyrolytic and photoassisted MOVPE growth of ZnSe us ing dimethylzinc triethylamine adduct (DMZn.TEN) and ditertiarybutylse lenium (DTBSe), diisopropylselenium (DIPSe) or diethylselenium (DESe) showed that low-temperature pyrolytic growth rates for all three Se pr ecursors 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 or ders of magnitude higher than that for DESe which shows that high hydr ogen 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 nitro gen was being incorporated in the ZnSe layer at temperatures below 400 degrees C. (C) 1998 Elsevier Science B.V. All rights reserved.