Design of a beamline for soft and deep lithography on third generation synchrotron radiation source

Abstract

ELETTRA is a third generation synchrotron radiation source. The energy spectrum allows the design of beamlines suitable for x-ray lithography from soft to hard x-ray wavelengths. An appropriate lithographic window for micro- and nanofabrication can be obtained by a combination of selected filters and mirrors. As the beamline is interfaced to a vertical x-ray stepper, a uniformity in the beam intensity better than 3% (3σ) in the horizontal direction has to be reached. The present beamline is designed by taking into account the main factors which can affect the beam quality, namely, thermal loading on mirrors and filters, slope errors, and surface roughness of the mirrors. The resulting lithographic resolution at soft x-ray wavelengths is better than 100 nm.