Groove design of vacuum chucks for hot embossing lithography

A preliminary study of the suitability of vacuum chucks for fixing of stamp and sample in a hot embossing lithography process was performed. Four inch test chucks were designed, featuring circular grooves and isolated holes of 0.7 to 2 mm size. The effect of these grooves was tested by imprint into PMMA with an unpatterned stamp. The processed samples showed a polymer thickness variation correlated with the groove locations, which could be measured with a profilometer. The thickness variations found were of different type when polymers of different molecular weight were used. Under realistic embossing conditions, values of up to 70 nm were measured. From the experiments, an allowable groove width of < 1 mm could be deduced. (C) 2002 Elsevier Science B.V. All rights reserved.