This paper describes the investigation on the feasibility of current coater/developer processes to the 157-nm lithography from the viewpoint of critical dimension (CD) control. The effect of coating, bake, and development process on the CD of a 157-nm resist, where fluorine is introduced in the side chain, is studied. A KrF and ArF resist is also used for comparison. Firstly, as for the coating process, the coverage performance and the film thickness uniformity of the 157-nm resist shows that the current coating methods are feasible to 157-nm resist, even though the 157-nm resist is highly hydrophobic. Secondly, as for the bake process, the post exposure bake (PEB) temperature dependence of CD for the 157-nm resist is found to be lower than that for 248 and 193-nm resist. This means that our current PEB temperature control system, which is suitable for 248 or 193-nm resist, is also effective for the 157-nm resist. Thirdly, as for the development process, it is found that a static puddle formation process shows a smaller line edge roughness (LER) than a dynamic puddle formation process. Therefore, the static puddle formation process, with the use of linear drive (LD) developer nozzle for instance, is attractive for the 157-nm resist process. Lastly, from the viewpoint of contamination control, it is found that the amine level should be controlled to be less than 0.1ppb in order to prevent the CD change during post exposure delay (PED) for the 157-nm resist.
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