Fabrication of Au gratings by seedless electroplating for X-ray grating interferometry

High quality gratings are among the key elements for successful imaging with X-ray grating interferometry. Grating fabrication, specifically of absorption gratings, with high aspect ratio and large area, is a great challenge from a microfabrication point of view. In this paper the fabrication of absorption gratings by seedless electro-plating of gold in high aspect ratio silicon moulds that are fabricated by deep reactive ion etching (Bosch process) is presented. We report on our latest results and discuss the possibility of reducing the grating period down to 1.3 mu m. In addition, the quality of the gratings is assessed by performing visibility measurements and imaging various samples on a compact in house X-ray grating interferometer.