Achromatic Talbot lithography with nano-ring masks for high-throughput periodic patterning

Abstract

Periodic patterning is important for various scientific and technological applications, especially in the nanoscale. Achromatic Talbot lithography (ATL) utilizing extreme ultraviolet (EUV) wavelengths, notably 13.5 nm, is a powerful lithographic technique enabling high-resolution and high-throughput nanopatterning over large areas. Improving the resolution and the throughput of the technique requires elaborate designs based on simulations and nanofabrication of transmission diffraction gratings on thin silicon nitride membranes. Our simulations point to the fact that compared to conventional ATL masks with hole arrays, masks consisting of annular rings and intersecting annular rings show increased performance in terms of throughput. A set of masks with uncrossed and crossed annular rings have been nanofabricated and exposed with spatially coherent synchrotron EUV light and the experimental results confirm our theoretical predictions that masks with annular rings and crossed rings yield dot arrays with improved throughput. The presented technique may enable applications in science and technology where large-area and periodic nanopatterning is needed.