Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (7): 1370-1376.doi: 10.3866/PKU.WHXB201405061

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Structure and Orientation Analysis of Iron Silicide Epitaxially Grown on Si Substrates

LI Xu1,2, ZOU Zhi-Qiang1,2, LIU Xiao-Yong1, LI Wei1   

  1. 1. Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, P. R. China;
    2. Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
  • Received:2014-02-24 Revised:2014-05-05 Published:2014-06-30
  • Contact: ZOU Zhi-Qiang E-mail:zqzou@sjtu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (61176017) and Innovation Program of Shanghai Municipal Education Commission, China (12ZZ025).

Abstract:

Iron silicides were grown on Si(110) and Si(111) substrates by the molecular beam epitaxy method at 650-920 ℃ and 920 ℃, respectively. Scanning tunneling microscopy observation showed that only nanowires (NWs) formed on Si(110), and the dimensions of the NWs increased with increasing growth temperature. The sizes of the NWs grown at 920 ℃ reached ~80 nm high, ~250 nm wide, and several μm long, and were much larger than NWs grown at 650 ℃, indicating that high temperature was favorable for NW growth. Electron backscatter diffraction characterization identified that the crystal structure of the NWs grown at 920 ℃ was β-FeSi2 with a single orientation of β-FeSi2(101)//Si(111)), β-FeSi2[010]//Si[110]. Iron silicides grown on Si(111) at 920 ℃ formed three-dimensional (3D) islands and ultra-thin films. The 3D islands were identified as the Fe2Si phase with hexagonal crystal structure and space group 164, and the cell constants at room temperature were a=0.405 nm and c=0.509 nm. The orientation relationship between the Fe2Si phase and the Si(111) substrate was Fe2Si(001)//Si(111), Fe2Si[120]//Si[112].

Key words: Scanning tunneling microscopy, Electron backscatter diffraction, Iron silicide, Nanowire, Three-dimensional island, Structure, Orientation relationship

MSC2000: 

  • O647