Oxygen ion implantation into the crystalline (001)Si substrates through the patterned SiO_2 structures : Evaluation of surface morphology

We have studied the formation method of very thin silicon-on-insulator structures with very thin buried oxide layers embedded in the Si(100) substrates by 10-keV O^+ ion implantations. O^+ implantations were performed through the patterned SiO_2 masks of various shapes with the areas of about several to several hundred micrometers square. In order to implant O^+ ions into laterally confined bulk silicon areas, we synthesized in advance thermally-formed SiO_2 films of ～100 nm-thick and partially etched for various shapes of square, circle, triangle, and rhombus by photolithographic process. These ～100-nm thick SiO_2 masks completely act as an absorber of 10-keV O^+ ions. In this study, we particularly investigated the structure and the surface morphology of the SiO_2-patterned Si substrates before and after oxygen implantation by atomic force microscope.