4, Bruker AXS, Karlsruhe, , Germany
2, IM2NP, Marseille, , France
3, SIMAP, Grenoble, , France
With the advent of high quality x-ray optics, several techniques have been proposed to exploit the imaging under Bragg conditions at synchrotron sources. Within the framework of the ESRF upgrade, a new dedicated instrument has been implemented on beamline ID01 at The European Synchrotron (ESRF). Since April 2017 this instrument is fully operational and has supplied users with Full Field Diffraction X-ray Microscopy (FFDXM) imaging adapted to various sample environments. Compared to more established scanning diffraction techniques, FFDXM offers fast, spatially resolved images on a large sample area without mechanical motions, perfectly suited for in situ and operando experiments.
The concept of FFDXM will be first demonstrated. A set of objective lens is placed downstream the sample to make a dark field image of the diffracted beam. At 6.5 meters away, the illuminated sample area (Field of View : 200×200 μm<span style="font-size:10.8333px">2</span>) is magnified and spatially resolved on a CCD camera with a resolution of 100 nm. Essentially an x-ray strain microscope, the FFDXM is capable of probing lattice tilt, strain and grain orientation at surfaces, buried interfaces or inside functioning devices, which is often unreachable for electron microscopy techniques.
Results of several user and in house experiments will be given next, to illustrate the principle of diffraction topography (strained STO), mosaicity (InGaN nano-pyramids) and strain (buried gas cavities in implanted Si wafers) mapping using FFDXM. Typical image acquisition time is around 1 sec; a complete set of measurement takes just a few minutes.
Thanks to its large FoV, short acquisition time and suitable resolution, the FFDXM is ideal for in situ and operando experiments. This is further demonstrated by two successful examples. In the first experiment, the evolution of strain and lattice tilt of the Si surrounding Cu Through Si Via (TSV) was studied during in situ annealing up to 500°C and during subsequent cooling. In the second experiment, the failure mechanism (defect formation) of planar Si anode was studied during operando cycling of a Li-ion battery.