Fabrication of astronomical x-ray reflection gratings using thermally activated selective topography equilibration

Thermally activated selective topography equilibration (TASTE) enables the creation of 3D structures in resist using grayscale electron-beam lithography followed by a thermal treatment to induce a selective polymer reflow. A blazed grating topography can be created by reflowing repeating staircase patterns in resist into wedgelike structures. Motivated by astronomical applications, such patterns with periodicities 840 and 400 nm have been fabricated in 130 nm-thick poly(methyl methacrylate) using TASTE to provide a base for x-ray reflection gratings. A path forward to integrate this alternative blazing technique into grating fabrication recipes is discussed.