Effective removal of global tilt from topography images of vicinal surfaces with narrow terraces

TL;DR

This paper introduces two image processing methods to effectively remove global tilt from topography images of vicinal surfaces, enabling clearer visualization of atomic structures despite small terrace widths and surface noise.

Contribution

The paper presents two novel procedures for correcting global tilt in topography images, improving visualization of atomic structures on vicinal crystal surfaces.

Findings

Both methods successfully remove tilt and noise.

Methods produce nondistorted images of atomic structures.

Applicable to vicinal Si surfaces.

Abstract

The main feature of vicinal surfaces of crystals characterized by the Miller indices (hhm) is rather small width (less than 10 nm) and substantially large length (more than 200 nm) of atomically-flat terraces on sample surface. This makes difficult to apply standard methods of image processing and correct visualization of crystalline lattices at the terraces and multiatomic steps. Here we consider two procedures allowing us to minimize effects of both small-scale noise and global tilt of sample: (i) analysis of the difference of two Gaussian blurred images, and (ii) subtraction of the plane, whose parameters are determined by optimization of the histogram of the visible heights, from raw topography image. It is shown that both methods provide nondistorted images demonstrating atomic structures on vicinal Si(556) and Si(557) surfaces.