Reconstruction and growth of Ag on hydrogen-terminated Si(111) surfaces

Initial stage of Ag film formation on hydrogen-terminated Si(111) surfaces at room temperature (RT) and high temperatures has been investigated by scanning tunneling microscopy. Ag atoms formed clusters on the hydrogen-terminated Si(111) at all temperatures, though the size and number were different in each case. When Ag was deposited at RT, relatively large and uniform Ag clusters were formed on the surface, compared with Ag deposition on a clean Si(111)-7×7 surface. On increasing the deposition temperature to 200 and 300°C, the size of Ag clusters became larger and the number of Ag clusters became less. When the surface where Ag was deposited on the hydrogen-terminated Si(111) at RT was annealed at 350°C, shallow and deep areas of 3− Ag structure appeared, due to hydrogen desorption. We demonstrate the usefulness of hydrogen termination for Ag deposition on the Si surface to fabricate flat and uniform thin films.