<title>Highly sensitive microresinoid siloxane resist for EB and deep-UV lithography</title>

Abstract

The multi-layer resist process is an essential technology for the future of both electronbeam (EB) and deep UV exposure. This process has been expected to reduce the proximity effect in EB exposure, and to planarize the high steps of device surfaces. A new bi-layer siloxane resist has been developed that gives negative tone images and has high sensitivity and high resolution for EB and deep UV lithography. High sensitivity was accomplished by introducing a chloromethyl-phenyl-alkyl (CPA) group, which has a resonant effect, as a functional group into the siloxane resin. For deep UV, the advantage of the siloxane resist is that is has a transmittance over 90%. The resist patterns of 0.2 micrometers at 10 (mu) C/cm2 and 0.3 micrometers at 80 mJ/cm2 were obtained for a shaped electron beam and deep UV, respectively. The O2 reactive ion etching (RIE) selectivity of the siloxane resist over the underlaid organic layer was about 30. The new siloxane resist is suitable for 64 M and 256 M DRAM lithography processes.