Ultrathin (0.9 nm - 15.3 nm) poly(methylmethacrylate) (PMMA) films prepared by the Langmuir-Blodgett (LB) technique have been explored as high-resolution electron beam resists. One-eighth micron lines-and-spaces patterns have been achieved by using a Perkin Elmer MEBES I pattern generation system as the exposure tool. The etch resistance of films with thicknesses greater than 4.5 nm is sufficient to allow patterning of chromium film suitable for photomask fabrication. Monolayer PMMA films containing 5 mol% pyrenedodecanoic acid (PDA) as a probe were prepared by transfer to the substrate at different surface pressures and characterized by fluorescence spectroscopy. The ratio of excimer to monomer emission intensity (Ie/Im) has a maximum value at ~ 10 dyn/cm, which may be related to a structural rearrangement in the film. Intrinsic bilayer LB PMMA films prepared at 1 and 19 dyn/cm have also been examined by transmission electron microscopy (TEM). The wrinkle-like surface topography observed in the 19 dyn/cm sample and not in the 1 dyn/cm sample suggests that the structure of the LB PMMA film depends on the transfer pressure.

Date Published: 30 January 1989
PDF: 11 pages
Proc. SPIE 1086, Advances in Resist Technology and Processing VI, (30 January 1989); doi: 10.1117/12.953037

Published in SPIE Proceedings Vol. 1086:
Advances in Resist Technology and Processing VI
Elsa Reichmanis, Editor(s)