Effect of coexisting (√7×√7) and (5×2) domains on the growth of CoSi2 islands on Si(111)

• Main Authors: Liu, YinMing, 劉殷銘
• Other Authors: Men, Fu-Kwo
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/79435607864849866274

碩士 === 國立中正大學 === 物理學系暨研究所 === 100 === Reconstructions introduced by depositing Au and Co on clean Si(111) surface have been studied by scanning tunneling microscopy (STM) and atomic force microscopy (AFM). By depositing a small amount of Au (Au coverage < 0.5 monolayers) onto a clean Si(111)-(7×7) surface, a coexistence of (7×7) and (5×2)/Au structures has been found on the surface. The areal ratio between the two structures can be controlled by Au coverage. After a sub-monolayer Co deposition, CoSi2 islands emerge on the (5×2)/Au domain whereas the (7×7) domain transforms into a (√7×√7) structure without the presence of CoSi2 islands, which would only appear at higher Co coverage, demonstrating a selective growth of islands on a surface. By investigating the size distribution of CoSi2 islands on a wide (5×2)/Au terrace or a collection of neighboring (5×2)/Au terraces, we are able to estimate the diffusion length of Co atoms under a simple diffusion model.