  We demonstrate high resolution extreme ultraviolet (EUV) coherent diffractive
imaging in the most general reflection geometry by combining ptychography with
tilted plane correction. This method makes it possible to image extended
surfaces at any angle of incidence. Refocused light from a tabletop coherent
high harmonic light source at 29 nm illuminates a nanopatterned surface at 45
degree angle of incidence. The reconstructed image contains quantitative
amplitude and phase (in this case pattern height) information, comparing
favorably with both scanning electron microscope and atomic force microscopy
images. In the future, this approach will enable imaging of complex surfaces
and nanostructures with sub-10 nm-spatial resolution and fs-temporal
resolution, which will impact a broad range of nanoscience and nanotechnology
including for direct application in actinic inspection in support of EUV
lithography.
