Fabrication and Testing of Cu/Al Multilayer Fresnel Zone Plate

In these experiments, the authors have produced Fresnel zone plate using Cu/Al multi-layer film, and then carried out evaluation procedures. They were successful in generating micro beam of 0.5 mu m Phi diameter from 8.54 KeV (1.45 Alpha deg ) x-ray. The reasons they have selected Al and Cu combination are: (1) they have relatively close thermal coefficient of expansion in bulk form, (2) as per references given at the end of this paper, there are numerous papers published regarding no zone disruption in the multilayer films. The Cu/Al multilayers are made by DC spattering method on the rotating gold wire of 47 mu m Phi as substrate on which 28 layers are formed and the cross section observed. After vapor deposition of each layer, the next layer is deposited 1 min later. The schematic diagram of rotating sample holder with wire substrate is shown with deposition parameters of these samples. The SEM photographs of concentric multilayers are provided for reference with x-ray diffraction (XRD) patterns.