Abstract
Unintentionally doped InN has been grown onto an atomically flat AIN intermediate layer on top of the Si(l 11) substrate using plasma-assisted molecular beam epitaxy (PA-MBE). Though there are lots of micrometer-size indium droplets randomly distributed on the top of the surface, the highest electron mobility of this InN thin film measured at room temperature by van der Pauw method is still higher than 1000 cmVV s with a carrier concentration of 5-8.9 × 10 18 cm -3 . A symmetrical X-ray rocking curve is measured and the full-width-at-half-maximum (FWHM) of this sample is 1089 arcsec. In the meantime, the threading dislocation (TO) density of this material is estimated to around 9.8 × 10 8 cm 2 - 7.5 x 109 cm"2 depending on the probing regions that are studied by the etching technique and field-emission scanning electron microscopy (FE-SEM). (2 × 1) in situ reflection high-energy electron diffraction (RHEED) patterns show that this sample is grown under In-rich environment with possible In-terminated surface. From the FE-SEM pictures which were taken from the samples after 10 minutes etching in hydrochloride, the surface morphology shows In-polarity-like patterns that coincide with those procured in RHEED. To select and grow a high-quality laminated AIN as intermediate layer is believed to be the major step in obtaining this high electron mobility InN thin film on Si substrate. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.