Hydrogen diffusion and chemical reactivity with water on nearly ideally H-terminated Si(100) surface

A nearly ideally H-terminated condition for a Si(100) 2 x I surface is determined from the dependence of the peak intensity and the linewidth of the coupled monohydride symmetric stretching vibration on the hydrogen exposure and exposure temperature, which has been investigated with infrared reflection absorption spectroscopy (IRRAS) using CoSi2 buried metal layer substrate. Even for nearly ideally H-terminated surfaces, the linewidth significantly changes depending on the hydrogen exposure and the exposure temperature. The concentration of deuterium atoms incorporated in the Si bulk is measured by temperature programmed desorption, and it is concluded that hydrogen diffusion into the subsurface of Si has a significant influence on the linewidth broadening. The chemical reactivity with water on the H-terminated Si surface is also investigated.