Interface-sensitive imaging by an image reconstruction aided X-ray reflectivity technique.

Jinxing Jiang,Kenji Sakurai,Keiichi Hirano

doi:10.1107/s160057671700509x

Abstract

Recently, the authors have succeeded in realizing X-ray reflectivity imaging of heterogeneous ultrathin films at specific wavevector transfers by applying a wide parallel beam and an area detector. By combining in-plane angle and grazing-incidence angle scans, it is possible to reconstruct a series of interface-sensitive X-ray reflectivity images at different grazing-incidence angles (proportional to wavevector transfers). The physical meaning of a reconstructed X-ray reflectivity image at a specific wavevector transfer is the two-dimensional reflectivity distribution of the sample. In this manner, it is possible to retrieve the micro-X-ray reflectivity (where the pixel size is on the microscale) profiles at different local positions on the sample.

Highlights

The significance of interfaces cannot be overstated, with their ubiquity from the hardware of the information age to the processes of life (Allara, 2005)
By combining the ’ scan (XRI) and scan (XR), it is possible to reconstruct the micro-X-ray reflectivity profiles at different local positions of the sample, where the inplane spatial resolution of the mXR is limited by the pixel size of the reconstructed X-ray reflectivity imaging (XRI) images
One can see a top-right hollow Ni triangle and a bottom-left spatial resolution of the mXR measurement is limited by the hollow rectangle; the contrast between the edge and the centre pixel size of the area detector, it is possible to go of the patterns originates from the difference in layer thick- beyond this limitation by, for instance, employing a postnesses between the edge and the centre of the deposited magnifier. (iii) Other than employing sophisticated optics to material

Summary

Introduction

The significance of interfaces cannot be overstated, with their ubiquity from the hardware of the information age to the processes of life (Allara, 2005). The authors have successfully developed a complementary novel X-ray reflectivity imaging (XRI) technique employing a wide monochromatic synchrotron beam (Jiang et al, 2016) and an area detector. The present work extends the technique to obtain more information on the samples by collecting a series of X-ray reflectivity images at different wavevector transfers. High voltage was applied and the sputtering conditions for the second Au pattern were as follows: Ar pressure 2 Pa; ion current 50 mA; sputtering time 60 s. The sputtering conditions to prepare different Ni patterns with different thicknesses were as follows: Ar pressure 2 Pa; ion current 260 mA; sputtering time 10 s (for the centre-right thin bar), 20 s (for the top-right triangle) and 30 s (for the bottom-left thick rectangle). The Ti layer covers the Au and Ni patterns such that the overall thickness of the heterogeneous sample is uniform and the Au and Ni regions are buried, separated layers

XRI technique

Raw data reduction

Data collection

Reconstructed X-ray reflectivity images

Quantitative analysis and outlook

Conclusion