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In current optical lithography, resolution is required to reach for 45 nm half-pitch and a chemically amplified resist (CAR) is used for a wide variety of applications. For ArF lithography beyond the 45 nm half-pitch, it is important to control pattern quality. The molecular design of a photo acid generator (PAG) is very important in the study to control not only acid strength but also acid diffusion length. Various novel PAGs that have different characteristics were synthesized for resist performance improvement. Acid molecular size was determined by molecular orbital (MO) calculation, and the acid diffusion coefficients (D) of these PAGs were evaluated by a bilayer method. As a result, it was found that acid diffusion coefficient (D) could not be controlled simply by adjusting anion molecular size. It may be presumed that the molecular interaction between acid generated by the exposure and polymer matrix areas is one of the most important key factors for controlling acid diffusion.

Guided by the paper [10] by Polyakov and Rychkov, we compute the second variational derivative of a wavy plane Wilson surface observable, to find that a necessary condition for a proposed surface equation to be satisfied in the large-N limit is that we are in the critical dimension D = 6.

Monte Carlo simulation of gel formation and surface and line-edge roughness in negative tone chemically amplified resists Surface and line-edge roughness in solution and plasma developed negative tone resists: Experiment and simulation J.Resists using polyphenol resin are introduced to reduce line-edge roughness ͑LER͒, and the spatial frequency characteristics of LER are evaluated. It is found that the long-period components of LER are suppressed in our low molecular-weight polyphenol resists. Device simulation using the measured LER shows that our polyphenol-based resist can drastically reduce the number of low-threshold-voltage ͑V th ͒ transistors compared with a conventional resist due to reduced long-period LER. Because LER impact is more serious as the transistor width shrinks, our results suggest that the use of the polyphenol-type resist will be more effective in improving device performance in future lithography process. In addition, it is shown that spectral analysis is a powerful tool for LER evaluation, especially from the viewpoint of device performance estimation.

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