Parallel nanostructure stripes were produced in an n-type Si substrate by implanting 30keV Ga+ ions from a focused ion beam source. Two sets of implantation were carried out. In one, the substrate was held at room temperature during implantation and, in the other, at 400C. Photo-emission electron microscopy was carried out on the samples. The implanted parallel stripes, each with a nominal dimension of 4000nm x 100nm, appeared as bright regions in the photo-emission images. Line scans of the intensities of the images were recorded along, and across, the stripes. The intensity profile at the edges of a line scan was broader for implantations carried out at 400C, than for those performed at room temperature. From an analysis of the intensity profiles, the lateral diffusion coefficient of Ga in silicon was estimated; assuming that the photo-emission intensity was proportional to the Ga concentration. The diffusion coefficient at 400C was estimated to be about 1.3 x 10−15m2/s. An asymmetrical diffusion profile was observed across the stripes and was attributed to the implantation sequence of the stripes, and to the associated defect distribution due to lateral straggling of the implanted ions.

Estimation of Diffusion Coefficient by Photoemission Electron Microscopy in Ion-Implanted Nanostructures. R.Batabyal, S.Patra, A.Roy, S.Roy, L.Bischoff, B.N.Dev: Applied Surface Science, 2009, 256[2], 536-40