ESCA microscopy beamline at ELETTRA

Abstract

Angle-resolved environmental X-ray photoelectron spectroscopy: A new laboratory setup for photoemission studies at pressures up to 0.4 Torr Rev. Sci. Instrum. 83, 093112 (2012) A new double imaging velocity focusing coincidence experiment: i2PEPICO Rev. Sci. Instrum. 83, 083105 (2012) Gamma-to-electron magnetic spectrometer (GEMS): An energy-resolved γ-ray diagnostic for the National Ignition Facility Rev. Sci. Instrum. 83, 10D311 (2012) Magnetic pulser and sample holder for time-and spin-resolved photoemission spectroscopy on magnetic materials Rev. Sci. Instrum. 83, 063906 (2012) Charged-particle spectroscopy for diagnosing shock ρR and strength in NIF implosions Rev. Sci. Instrum. 83, 10D901 (2012) Additional information on Rev. Sci. Instrum.The article describes the ESCA microscopy beamline dedicated to high spatia1 resolution quantitative and qualitative analysis on surfaces and interfaces. The scanning microscope is constructed to work both in transmission and photoemission within the photon energy range from 200 to 1200 eV with a spatial resolution of -0.1 pm. A Fresnel zone plate demagnifies the photon beam to submicrometer dimensions with 109-10" photons/s in the focus spot. A photodiode and a hemispherical electron energy analyzer are used as detectors for recording the transmitted x-rays and emitted photoelectrons, respectively. The operation modes in photoemission give the opportunity to obtain conventional energy distribution curve spectra from a microspot or a two-dimensional micrograph of the spatial distribution and local concentration of a selected element as the sample is mechanically scanned. For conductive specimen topography measurements of a selected surface area probed by SPEM are possible using a scanning tunnelling microscope. The first test images of a zone plate and an e-beam written specimen with 1 Frn2 Au squares on Si have shown a spatial resolution better than 0.2 ,um. 0 199.5 American Institute qf Plzysics.

Spectromicroscopy of the metastable interface studied by means of synchrotron radiation

“…More technical details about the beamline are published in Ref. [8]. Electron energy distribution curves (EDC) were measured by means of a hemispherical analyser (angle of emissionx 19') operated in the constant energyresolution mode (overall working energy resolution M 0.44 eV ) .…”

Mg and Si dopant incorporation and segregation in GaN

“…This ultra-high vacuum (UHV) setup [19][20][21] enables X-ray photoemission spectroscopy (XPS) measurements with high spatial resolution. This is achieved by refractive focusing of the incoming photon beam by means of a Fresnel zone plate, down to a focal spot size with a diameter of about 150 nm.…”

First Results from the ESCA Microscopy Beamline on ELETTRA

“…The working distance is about half the focal length, because an order sorting aperture should be placed between the zone plate and the sample. 1,3,7 The relationship between the focal length f, zone plate parameters (diameter D and outer zone width dr) and photon energy E (eV) are described by…”

“…7. From the 20È80% rise in the intensity across the knife edge, a spatial resolution of 150 nm was measured for a zone plate with a theoretical resolution of 122 nm.…”