ELEMENT-RESOLVED, VELOCITY-RESOLVED AND SPATIALLY-RESOLVED IMAGES OF KR+ SCATTERING AND RECOILING FROM A CDS SURFACE

Developments in ion scattering spectrometry and detector technology al low measurement of element-, velocity-and spatially resolved distribut ion patterns of scattered and recoiled atoms, forming the basis for a scattering and recoiling imaging spectrometry (SARIS). SARIS images ar e architectural fingerprints of surface short-range order. They exhibi t extreme sensitivity to structural details, providing a unique probe for determination of surface composition and structure. Quantitative a nalysis is obtained by comparison with simulated images using the scat tering and recoiling imaging code (SARIC). The SARIS technique is demo nstrated herein for analysis of the composition and termination of a C dS{0001} surface. Using 4 keV Kr+ primary ions, it is possible to obse rve separate images of Kr scattering from Cd and images of recoiled H, O, S and Cd atoms. The O and H atoms are impurities which are observe d on this surface, even after annealing to 700 degrees C. It is found that the Cd-terminated surface contains Cd atoms in the first layer an d S atoms in the second layer. The surface structure appears to be sta bilized by bonding of the first-layer Cd atoms to O or OH moieties. (C ) 1998 Elsevier Science B.V.