The evolution of surface microstructure on bismuth thin film deposited by molecular beam deposition method is investigated. Morphological, topographical, structural, and electrical property changes of the film with various thicknesses are studied by means of AFM, XRD, XRR, and 4-point probe. Drastic change of surface grain in shape, which transforms from round shape to polyhedral shape, is detected around 13-18 nm film thickness. Abrupt horizontal profile change of surface grain is verified with power spectral density (PSD) function. At this threshold thickness, the film shows very low roughness value and surface area ratio. Then both increase steeply as the film thickness surpasses the thickness. As the bismuth film is deposited thicker, it has textured structure and high roughness on surface. With increment of the thickness, the electrical sheet resistance of the films is significantly decreased. We explain this surface microstructure evolution on the bismuth film with the evolutionary selection model.
Bibliographical noteFunding Information:
This work was supported by the Korea Institute of Science and Technology ( 2E23150 ) and by the Converging Research Center Program through the ministry of Education, Science and Technology ( 2011K000589 ).
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)