Hard x-ray grazing-incidence ptychography: large field-of-view nanostructure imaging with ultra-high surface sensitivity

The morphology and distribution of nanoscale structures, such as catalytic active nanoparticles and quantum dots on surfaces, have a significant impact on their function. Thus, the capability of monitoring these properties during manufacturing and operation is crucial for the development of devices that rely on such materials. We demonstrate a technique that allows highly surface-sensitive imaging of nanostructures on planar surfaces over large areas. The capabilities of hard x-ray grazing-incidence ptychography combine aspects from imaging, reflectometry, and grazing-incidence small angle scattering in providing images that cover a large field of view along the beam direction while providing high surface sensitivity. For homogeneous samples, it yields a surface profile sensitivity better than 1 nm normal to the surface, with a poorer resolution in the sample surface plane, (i.e., along the beam and transverse to the beam). Like other surface scattering methods, this technique facilitates the characterization of nanostructures across statistically significant surface areas or volumes but with additional spatial information. In this work, we present a reconstructed test object spanning 4.5 mm × 20 µm with 20 nm high topology.