Fabrication of gratings on curved substrates using electron-beam lithography

The next generation of reflection gratings for future high-energy space observatories needs a high degree of customization. Making such gratings will require the use of increasingly complex nanofabrication techniques. One of the current challenges we are investigating is the precise patterning of grooves onto curved substrates, which is needed for effective aberration-correction. We report on our use of electron-beam lithography to pattern large-format gratings on cylindrical substrates. We will discuss the fabrication steps involved, from the alignment of the substrate to the actual writing strategy, and we will summarize our characterization efforts based on interferometric measurements. Future steps will be discussed, including the patterning of a segmented X-ray mirror.