Atomic force microscopy studies of cross-sections of columnar thin films

In this paper, the columnar structure of TiO2 and HfO2 thin films prepared on silicon wafers is studied using two modifications of atomic force microscopy (AFM), i.e., by standard AFM and micro-hardness modification of AFM. These methods are applied to the cross-sections of the films created by fracturing samples consisting of substrates covered with the films under investigation. It is shown that the edge of the film in the cross-section does not cause an obstacle for scanning the AFM images corresponding to both the AFM modifications mentioned above. In this paper it is also shown that the micro-hardness contrast mode of AFM is the more useful technique for imaging the columnar structure of films than standard AFM when film cross-sections exhibit artificial defects originated as a consequence of fracturing the films.