In situ XAS and XRF study of nanoparticle nucleation during O3-based Pt deposition

Mobile setup for synchrotron based in situ characterization during thermal and plasma-enhanced atomic layer deposition

“…Alternatively, double kapton windows can be used, with differential pumping in between both windows to enable a sufficiently low base pressure in the main chamber. 19 A CF100 beryllium window is mounted on one of the side flanges as an entrance window for the synchrotron beam. For XRF and XAS measurements, the 0.2 mm thick CF35 beryllium window is used as an exit window and is either installed on a vertical CF100 to CF35 reducer flange or on one of the CF35 corner flanges pointing to the center of the chamber (Figure 1(a), see also Section III).…”

“…In recent years, several groups have explored extending this concept of using light to study ALD growth towards the x-ray part of the electromagnetic spectrum. 8,[10][11][12][13][14][15][16][17][18][19][20][21][22][23] Indeed, when an ALD reactor is equipped with x-ray transparent windows (e.g., beryllium, graphite, or kapton), then the film can be (intermittently) exposed to x-rays during growth, and a wide range of x-ray based thin film characterization techniques can be used for in situ characterization, as recently reviewed by Devloo-Casier et al 17 Since ALD is typically used for nanocoatings with a thickness of 0.1 to several tens of nanometers, while xrays typically penetrate several micrometers deep into most materials, it is challenging to obtain a sufficient signal to noise ratio for x-ray based characterization techniques, in particular when targeting acquisition rates of 1-60 s in order not to interfere too much with the standard exposure cycle of the ALD process. Therefore, while lab-based x-ray sources are used routinely for ex situ analysis of, e.g., the crystallinity of ALD grown films, the in situ studies typically require the high photon flux that can only be offered by synchrotron based sources.…”

“…To enable such synchrotron based experiments, a dedicated ALD setup is required that is preferably mobile so that it can be used at different beamline end stations (enabling different x-ray based characterization techniques), preferably at different synchrotron user facilities. In recent years, "in situ" setups have been developed at the National Synchrotron Light Source (NSLS I) at Brookhaven National Lab (by temporarily transforming a multi-purpose UHV chamber at beamline X21 into an ALD reactor), 10,24 at the Pohang Light Source (PLS), 14 at the Advanced Photon Source (APS) at Argonne National Laboratory, 21 at Stanford Synchrotron Radiation Lightsource (SSRL), 20 and at SOLEIL, 19,22 while "in vacuo" setups have been developed at BESSY II 25,26 and at SSRL, 27,28 mainly targeting XPS.…”

“…In situ XAS during ALD allows probing the local atomic environment and provides information such as the level of oxidation, coordination numbers, and bond lengths. 12,16,19 GISAXS is a scattering technique used to study the morphology of nanoscale objects at surfaces, interfaces, or in thin films. 30 In ALD research, in situ GISAXS has been applied to investigate conformal deposition in porous thin films 18 and on a layer of semiconducting quantum dots.…”

2015 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and their applications

“…The XRF maps revealed a homogeneous distribution of the Co ions implanted along the nanowires, while the XANES data indicated a substitutional incorporation of Co 2+ into the wurtzite ZnO host lattice. Filez et al 405 used XAS and XRF techniques to study in situ NP nucleation during Pt deposition. Johannes et al 403 reported enhanced sputtering and incorporation of Mn in implanted GaAs and ZnO nanowires.…”