HIGH DEPTH RESOLUTION ANALYSIS OF CU SI(111) 5 X 5 STRUCTURE WITH MEDIUM-ENERGY ION-SCATTERING/

High depth resolution measurements under the glancing take-off conditi on of medium energy ion scattering (MEIS) were carried out in order to determine the interlayer distances of the Cu/Si(111) ''5 x 5'' incomm ensurate structure. The experimental spectra were analyzed using a Mon te Carlo simulation. In the simulation, the single electron excitation and the plasmon excitation were taken into consideration as the inela stic energy loss. The energy straggling was estimated by the calculati on of the energy spectra for the Si(111) 7 x 7 surface, whose structur e was well established. The distance between two Cu layers in the inco mmensurate layer was obtained to be about 0.06 nm, and that between Cu and Si layers in the incommensurate layer to be 0.006 nm. Also the di stance between the Si layer in the incommensurate layer and the first Si layer of the substrate is determined to be 0.19 nm. (C) 1998 Elsevi er Science B.V.