X-ray micro-beam focusing system for in situ investigation of single nanowire during MBE growth

A ternary Fresnel zone plate (FZP) has been fabricated and installed at the beamline 11XU of SPring-8, in the aim of in situ studies on the growth of semiconductor nanostructures. The FZP is designed for an X-ray energy of 9.5 keV for the first-order diffraction, which is isolated by an order sorting aperture (OSA) inserted 450 mm after the FZP. The focal length of this FZP is 650 mm. The full width at half maximum of the focused beam profile was estimated to be 1.17 μm (H) × 1.38 μm (V) by the dark-field knife-edge scan. Using this FZP, micro-beam diffraction of an as-grown single InAs NW was carried out to show the feasibility of in situ study during growth.