| AVS 54th International Symposium | |
| Surface Science | Thursday Sessions |
| Session SS-ThP |
| Session: | Surface Science Poster Session |
| Presenter: | S.Y. Chiam, Imperial College London, Singapore |
| Authors: | S.Y. Chiam, Imperial College London, Singapore A.C. Huan, Institute of Materials Research and Engineering, Singapore W.K. Chim, National University of Singapore J. Zhang, Imperial College London, Singapore J.S. Pan, Institute of Materials Research & Engineering, Singapore |
| Correspondent: | Click to Email |
Initial adsorption sites of metal on Si is an increasingly important area of research especially for growth of thin films for low dimensional devices. Growth and simulation of heterojunction thin films on Si often require a more detail information about the position and bonding of the adatom. For instance, study of Sr with experimental and theoretical methods have lead to a better understanding of Sr adatom’s preferred environment and gave insights into subsequent growth of epitaxial thin film, in particular, SrTiO3. In this work, we have investigated the initial adsorption of transition metal yttrium (Y) on Si(001). Y although formally a transition metal, have very similar valence electronic properties with the lanthanide family, including lanthanum. In Si based electronics, yttrium silicide, yttrium silicate and yttrium oxide are all potential thin films for source-drain contacts, infrared-detectors, and gate dielectrics. Furthermore, information about Y adsorption sites can aid in the design and growth of ternary or quaternary oxides (eg. LaYAl2O3). We have examined the real-time deposition of Y on Si(001) 2X1 by mounting a EFM evaporator source on the STM chamber. Therefore, we have observed the deposition of sub-monolayer coverage of Y atom on the same area of clean Si image thereby reducing any errors that might arise from adsorption of other species in UHV. Our work shows that yttrium adsorbs primarily on dimer bond instead of the cave site as predicted from a theoretical simulation of La on Si(001). We’ve examine the possible structure for such an adsorption and discuss about its stability and its bonding character using both STM and UPS.