나노 압입 실험을 통한 Al/Ti 다층박막의 기계적 물성치 측정

Abstract

In this study, the mechanical properties of multilayered thin film are investigated. Goal of this study is to find the effects due to bilayer thickness of the film on the mechanical properties (hardness and elastic modulus). Al/Ti multilayer thin films with different bilayer thickness of 10nm, 25nm and 50nm were fabricated by the electron beam physical vapor deposition. After fabrication, the film was annealed at 600℃ for 1min or 2min to verify grain size. The thickness is observed and measured by cross-sectional TEM(Transmission Electron Microscope) to make sure that they are laminated structure.X-ray diffraction and nanoindentation were used to estimate grain size and the mechanical properties of the film. By comparing the results from X-ray diffraction with those from nanoindentation, the hardness enhancement owing to grain size effect could be removed. The elastic modulus of Al/Ti multilayer thin films at the bilayer thicknesses of 10nm or 25nm shows 140±10GPa which indicates ‘supermodulus effect.’