▎ 摘　　要

Graphene sheets were formed on a Si substrate with a 300-nm-thick SiO2 layer. The graphene sheets partially covered the SiO2 surface. Ge was deposited on the surface by sputtering. The fabricated samples were evaluated with Raman spectroscopy and atomic force microscopy. We found that Ge was formed on the graphene surface selectively when the substrate temperature was 450 degrees C or higher during the deposition. The results of the Raman spectroscopy indicated that sp(3) defects were introduced into the graphene sheets after the deposition. Such defects can be an important factor in the selective adsorption of Ge on graphene sheets because sp(3) defects are highly reactive. A growth temperature of more than 450 degrees C was needed for the selective deposition, indicating that the surface diffusion of the Ge adatoms on the insulating surface during the deposition is also important. The selective deposition of Ge on the graphene sheets is considered to be due to the sp(3) defects introduced into the graphene sheets and surface diffusion of the Ge adatoms on the SiO2 surface. This direct-patterning technique on insulators can be utilized for various materials that can be deposited by sputtering.