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ABSTRACFWe designed a new chemical amplification resist for ArF and KrF excimer lithography. The resist comprises alicyclic the copolymer of adamantylmethacrylate and tert-butylmethacrylate with triphenylsulfonium hexafluoroantimonate as a photo acid generator. This resist is highly transparent at KrF and ArF wavelengths because it has no aromatic and its dry etch resistance is comparable to that of Novolac resist.The lithographic performance of this resist was evaluated using a KrF excimer laser stepper. A less than 0.5 micron line and space pattern profile was obtained with our resist.

To use a TMAH (tetramethylanmonium hydroxide aqueous solution) developer with a resist based on adamantylmethacrylates, we proposed a cleavable adamantyl ester by protonic acid. We found that a 2-methyl-2-adamantyl ester was cleavable by protonic acid and poly(2MAdMA) (2-methyl-2-adamantylmethacrylate) worked as a chemically amplified resist with good sensitivity. We achieved high resolution by improving the adhesion.The 2MAdMA-MAA (methacrylic acid) resist achieved 0.165 pm L/S with 3.0 mJ/cm2 in ArF evaluation using a dilute TMAH developer. We could use a 2.38% TMAH developer by introducing 2MAdMA to the strongly polar acid labile protect group, OCMA (3-oxocyclohecylmethacrylate) or MLMA (mevalonic lactone methacrylate), which had good adhesion. We obtained fine patterns below 0.20µm at below 10 mJ/cm2 in ArF evaluation with 2.38%TMAH developer. We achieved a minimum resolution with 0.15 pm L/S patterns and a D.O.FE of 0.6 pm at 0.18 pm L/S patterns using a 2MAdMA-MLMA resist.

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