Comparison between the atomic force microscopy and x-ray reflectivity on the characterization of the roughness of a surface

Abstract

X-ray reflectivity and atomic force microscopy are two common tools in characterizing the surface roughness. However, the measurement results reported by these two methods were usually not consistent between each other. In this work, polished sapphire wafers with different surface roughness were prepared and measured by both methods. To understand the disagreement, a possible interpretation for X-ray reflectivity and atomic force microscopy on the characterization of the surface roughness is described. The difference in the X-ray reflectivity measurement, the X-ray beam covers a larger area of few mm 2 on the sample, while the atomic force microscopy probes only a local area (around µm 2 ). In general, the surface roughness measured by atomic force microscopy should be smoother than that obtained by X-ray reflectivity due to the convolution of tip shape of atomic force microscopy and the short wavelength of probing X-rays. However, the surface contamination of the sample and the atomic force microscopy environment complicate the measurements for both methods, especially, for these samples with root-mean-square roughness less than 1 nm.

Surface Topography of Si/TiO2 Stacked Layers on Silicon Substrate Deposited by KrF Excimer Laser Ablation

“…X-ray Reflectivity (XRR) was used in order to examine the roughness and the thickness of the TiO 2 layer. The roughness determined in the XRR measurement shown in Figure 8a for the TiO 2 layer obtained in optimal conditions (sample S2) is 0.37 nm, being in agreement with the AFM data for the same layer (Table 1) [42].…”

Thermal Atomic Layer Etching of Nickel Using Sequential Chlorination and Ligand-Addition Reactions

“…However, earlier comparisons of surface roughness determined using AFM and XRR measurements have also not been in exact agreement. 44,45 Both the AFM and XRR measurements record rougher surfaces after the removal of more than 20 Å from the initial Ni film. Similar results for the surface roughness were observed for Ni ALE at 150 °C.…”

Formation of wrinkles on graphene induced by nanoparticles: Atomic force microscopy study

“…The wrinkles were located by the threshold masking method. Using the grain analysis, the Awr values for individual samples were determined (Figure 3 The autocorrelation functions, HHCF of decorated substrates and whole GN layers (which is connected with the ability of surface diffusely scatters the incident light [52,56,59,60]) are summarized in the Supplementary information file (Figure S10 and S11).…”