INP(001) SURFACE-STRUCTURE AND INTERACTION WITH ATOMIC-HYDROGEN

Structure and electronic properties of clean and hydrogen-terminated I nP surfaces are studied by reflectance anisotropy spectroscopy (RAS), Auger electron spectroscopy (AES), high resolution energy electron los s spectroscopy (HREELS), low energy electron diffraction (LEED) and so ft X-ray photoelectron spectroscopy (SXPS). Clean surfaces were prepar ed either by sputtering and annealing or decapping (As/P-cap). Both pr eparation methods lead to the same type of (2 X 4) surface structure w ith slightly different ratios of indium to phosphorus. The correspondi ng structural changes of the surface during hydrogen exposure are inve stigated by LEED, surface electronic modifications are observed by RAS . Medium exposures of atomic hydrogen break In bonds at the surface wh ile high exposures lead to an In enrichment of the surface. With incre asing hydrogen exposure the optical anisotropy is lifted. (C) 1998 Els evier Science B.V.