Surfactant effect of hydrogen for nickel growth on Si(111)7X7 surface

In this report we will describe a 'surfactant effect' of hydrogen for nickel on Si(111)7 x 7 surface terminated by atomic hydrogen prior to Ni-deposition. For hydrogen detection, time-of-flight type electron-stimulated desorption (TOF-ESD) spectroscopy was used complementary with Auger analysis, LEED and RHEED, 2-monolayer (ML) Ni film was grown on a Si(111)7 x 7 surface in layer-by-layer growth mode and changed to 3-dimensional Stranski-Krastanov mode over 2 ML. The 7 x 7 LEED pattern was observed to 2 ML(-) of Ni. The Si-LVV Anger peak was observed to IO ML. In contrast, a hydrogen-terminated surface showed d-7 x 7 structure where the ESD measurement showed 1.5 ML of hydrogen, the Si-LVV Auger peak had disappeared at 7 ML of Ni taking layer-by-layer mode, namely, Frank-Van der Merwe growth mode.