| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Thin Films | Tuesday Sessions |
| Session TF-TuM |
| Session: | Nanostructured Surfaces & Thin Films II |
| Presenter: | Ja-Yong Koo, Korea Research Institute of Standards and Science (KRISS), Republic of Korea |
| Authors: | E. Seo, Korea Research Institute of Standards and Science (KRISS), Republic of Korea D. Eom, Korea Research Institute of Standards and Science (KRISS), Republic of Korea J.-M. Hyun, Sookmyung Women's University, Republic of Korea H. Kim, Sookmyung Women's University, Republic of Korea J.-Y. Koo, Korea Research Institute of Standards and Science (KRISS), Republic of Korea |
| Correspondent: | Click to Email |
C atoms can be incorporated into the 4th delta-layer (0.4 nm deep) under the Si(001) surface upto the density of 0.125 monolayer with the c(4x4) surface reconstruction.
We investigated the incorporation of C atoms into Si(111)-7x7 surface by using scanning tunneling microscopy. The C atoms are extracted by thermal dissociation of CO molecules adsorbed on the Si(111)-7x7 surface. Previous studies negate adsorption of CO molecules on this surface even at low temperatures near 10 K. However, we find that every surface dangling bond on the Si(111)-7x7 surface can bind strongly with the C atom of a CO molecule even at temperatures higher than room temperature. Especially CO molecules bind with Si adatoms in three configurations; one <on-top> and two <back-bond inserted> structures.
By thermal annealing, C atoms are incorporated under the Si adatoms of Si(111)-7x7 surface. The maximum density of incorporated C atoms on Si(111)-7x7 is low compared with that on Si(001)-2x1. At high density, C atoms are swept away from the 7x7 reconstructed surface due to the excessive surface stress, forming irregular SiC phases along the step edge.
Regular and uniform C-incorporated Si(111)-√3x√3 reconstruction is not formed on this Si wafer surface.