Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2006, Vol. 17 ›› Issue (4): 202 doi: 10.1016/S1001-8042(06)60038-9

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Probing Co/Si Interface Behaviour by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM)

PAN J. S.1,* LIU R. S.2 TOK E. S. 1,2   

  1. 1Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602;
    2Department of Physics, National University of Singapore, Kent Ridge, Singapore 119260
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PAN J. S. LIU R. S. TOK E. S.. Probing Co/Si Interface Behaviour by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM).Nuclear Science and Techniques, 2006, 17(4): 202     doi: 10.1016/S1001-8042(06)60038-9

Abstract: In this work, we investigate the Co-Si reaction, the Co growth mode at room temperature, diffusion be-haviour as well as morphology evolution during annealing on both H-terminated and clean Si(001) and Si(111) sur-faces. From in-situ X-ray photoelectron spectroscopy (XPS) investigation, “Co-Si” reaction appears to occur on both H-terminated and clean surfaces at room temperature (RT) and the silicide crystallinity is improved upon annealing. Co growth mode on H-terminated Si surfaces occurs in a pseudo layer-by-layer manner while small close-packed is-land growth mode is observed on the clean Si surface. Upon annealing at different temperatures, Co atom concentra-tion decreases versus annealing time, which in part is attributed to Co atoms inward diffusion. The diffusion behav-iour on both types of surfaces demonstrates a similar trend. Morphology study using ex-situ atomic force microscopy (AFM) shows that the islands formed on Si(001) surface after annealing at 700 °C are elongated with growth direc-tions alternate between the two perpendicular [\bar{1}10] and [110] directions. Triangular islands are observed on Si (111) surface.

Key words: Cobalt, Silicon, Metal-semiconductor interfacial reaction, Hydrogen termination, Growth mode, Diffu-sion, Surface morphology, XPS, AFM