Thermal effects in the size distribution of SiC nanodots on Si(111)

We have used scanning tunneling microscopy (STM), Auger electron spectroscopy (AES) and X‐ray Photoelectron spectroscopy (XPS) to investigate the formation of nanoscopic structures on Si(111), from wafers with a high bulk C concentration. The samples were prepared by long time thermal annealing of the silicon samples, followed by a high temperature flash in ultrahigh vacuum. An increased surface C con‐ centration is induced by segregation from the bulk. The surface is found to roughen on the nanososcopic length scale, exhibiting a random distribution of nanostructures. The height range of the structures varies between 2 and 20 nm. The size distribution is strongly dependent on the low‐temperature preparation con‐ ditions. Ex‐situ XPS measurements reveal the formation of SiC bonds, thus confirming the nanodots are formed by a surface recombination of SiC. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)