Résumé
We present results for the MOVPE growth of InN films onto sapphire substrates, by direct growth or using a GaN buffer layer. As opposed to common belief, it is shown that a low V/III molar ratio has to be used in order to achieve high quality films. Using the parameters that are presented here, we were able to grow mirror like layers on 2 inch sapphire wafers, with a reproducible mobility of 800cm(2)/VS. This is the best value obtained to date for MOVPE growth. Reflectivity and absorption studies of our layers reveal a marked structure around 1.2 cV, at room temperature. InN quantum dots were also grown on to GaN buffer layers. The dot size and density was controlled by tuning the growth temperature and the molar V/III ratio. The quantum dots that we have grown are flat hexagons, with an aspect ratio of 0.1-0.16, and height down to 2 nm. (C) 2004 Elsevier B.V. All rights reserved.