X-ray ptychography is a scanning variant of coherent diffractive imaging with the ability to image large fields of view at high resolution. It further allows imaging of non-isolated specimens and can produce quantitative mapping of the electron density distribution in 3D when combined with computed tomography. The method does not require imaging lenses, which makes it dose efficient and suitable to multi-keV X-rays, where efficient photon counting, pixelated detectors are available. Here we present the first highly resolved quantitative X-ray ptychographic tomography of an extended object yielding 16 nm isotropic 3D resolution recorded at 2 Å wavelength. This first-of-its-kind demonstration paves the way for ptychographic X-ray tomography to become a promising method for X-ray imaging of representative sample volumes at unmatched resolution, opening tremendous potential for characterizing samples in materials science and biology by filling the resolution gap between electron microscopy and other X-ray imaging techniques.
Selective-area atomic layer deposition (ALD) was achieved using poly(methyl methacrylate) (PMMA) films as growth inhibiting mask layers. The PMMA films were prepared from PMMA-toluene solution by spincoating and patterned by UV lithography through a mechanical mask. The patterned PMMA films were tested in several ALD processes, both noble metals and oxides. The tested noble metal processes were iridium, platinum, and ruthenium, and the oxide processes were Al 2 O 3 and TiO 2 . Al 2 O 3 was deposited using AlCl 3 and H 2 O and trimethylaluminum (TMA) and H 2 O. TiO 2 was deposited using Ti(OMe) 4 and H 2 O. The growth temperatures were 250-350 °C.
X-ray microscopy based on Fresnel zone plates is a powerful technique for sub-100 nm resolution imaging of biological and inorganic materials. Here, we report on the modeling, fabrication and characterization of zone-doubled Fresnel zone plates for the multi-keV regime (4-12 keV). We demonstrate unprecedented spatial resolution by resolving 15 nm lines and spaces in scanning transmission X-ray microscopy, and focusing diffraction efficiencies of 7.5% at 6.2 keV photon energy. These developments represent a significant step towards 10 nm spatial resolution for hard X-ray energies of up to 12 keV.
Selective-area atomic layer deposition (ALD) was studied using poly(vinyl pyrrolidone) (PVP) films as growth-preventing mask layers. The PVP films were prepared by spin coating and patterned by UV lithography. The PVP films were tested in several ALD processes: iridium, platinum, ruthenium,
Al2normalO3
, and
ZrO2
. The deposition temperatures were
250–300°C
. In general, the PVP film passivated the surface against the noble metal processes, but the oxide films grew on PVP. However, the oxide films did not grow through the PVP film on the substrate surface and, therefore, the films could still be patterned, though with more of a lift-off method rather than with pure selective-area ALD.
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