OMVPE growth of ZnSe and ZnS xSe 1-x using methylselenol as a selenium source

Abstract

We investigated the usefulness of methylselenol (CH 3SeH, MSeH) as a new selenium source in organometallic vapor-phase epitaxy (OMVPE) of ZnSe and ZnS xSe 1-x. Since this precursor has a high vapor pressure (760 Torr at 12°C), it was supplied as a gas diluted with H 2. The growth temperature was successfully reduced (typically 400°C) compared with that in the growth using dialkyl-compounds, without serious gas-phase prereaction. The low growth temperature improved the photoluminescence properties of ZnSe. A ZnS 0.07Se 0.93 epilayer closely lattice-matched to GaAs substrate had an excellent FWHM value in X-ray rocking curve (19 arc sec), and exhibited strong near band-edge emissions in photoluminescence. For iodine-doped ZnS 0.07Se 0.93 epilayers, carrier concentration of 5 x 10 17 cm -3 was attained without serious degradation of epilayer qualities. Thus MSeH was found to be a promising Se source in OMVPE of II–VI compounds including Se.