Investigation of self-organized steps and terraces in SrTiO₃ (001) substrate inclined in [110] direction by scanning tunneling microscopy

The features of self-organized steps and terraces on SrTiO₃ (001) substrates inclined in a [110] direction with various inclined angles (α) have been investigated by scanning tunneling microscopy (STM). The well-defined triangular step edges forming nanodot structures are observed on the surface. The surface features of SrTiO₃ substrates inclined in the [110] direction consist of the combinational features of substrates in the [100] and [010] inclined directions. Details of the distributions of step heights, terrace widths and lengths of step edge dependent on inclined angles are described. The formation of double, triple and triple half steps is observed in self-organized substrates. The surface after self-organization maintains the same ratio of step height to terrace width. The terminations of TiO₂ and SrO planes on the surface are observed visually by an analysis of surface structures. The inclined angle of the substrate inclined in the [110] direction is expected to be an important factor for controlling the density of nanodot structures.