"Vicinal" surfaces, with equally spaced monoatomic steps, can be obtained by thermally annealing single crystals of materials like sapphire or silicon. We have observed the diffraction of a helium-neon laser beam on the monoatomic steps of a (0 0 0 1) vicinal sapphire wafer surface. Diffraction angles were in the range 40-50°, in agreement with the AFM-measured terrace length. Both sides of the wafer gave rise to lowest-order diffracted beams. This method allows one to determine surface characteristics such as the direction, average length and regularity of the terraces on the area illuminated by the laser. In the tested sample the direction of the crystal C axis could be shown to be uniform to within 5″ over a 12 mm area of the sample. © 2002 Elsevier Science B.V. All rights reserved.
Lintz, M., & Bouchiat, M. A. (2002). Observation of the diffraction of a helium-neon laser beam on the monoatomic steps of a vicinal sapphire surface. Surface Science, 511(1–3). https://doi.org/10.1016/S0039-6028(02)01569-8