INFLUENCE OF OPTICAL-PARAMETERS OF SYNCHROTRON-RADIATION LITHOGRAPHY BEAMLINE ON PATTERN REPLICATION

The influence of the angular divergence of X-rays incident on an X-ray mask and the exposure spectrum, which are the optical parameters dete rmined by the geometric and band-pass properties of beamline optics an d the synchrotron radiation (SR) spectrum, on resist pattern replicati on on various substrates was investigated. Using a compact storage rin g as the SR source, we confirmed that there is no problem in 0.15-mu m -feature pattern replication on Si substrate, regardless of the type o f beamline optics. However, we found that an undercut or undeveloped p ortion inevitably occurs on a substrate which is covered with high ato mic number material film, but this overexposure of resist can be reduc ed in a beamline with a broad band exposure spectrum.