No abstract

No abstract

The advantages of NTI process in EUV is demonstrated by optical simulation method for 0.25NA and 0.33NA illumination system with view point of optical aerial image quality and photon density. The extendablity of NTI for higher NA system is considered for further tight pitch and small size contact hole imaging capability. Process and material design strategy to NTI were discussed with consideration on comparison to ArF NTI process and materials, and challenges in EUV materials dedicated to NTI process were discussed as well. A new polymer was well designed for EUV-NTD process, and the resists formulated with the new polymer demonstrated good advantage of resolution and sensitivity in isolated trench imaging, and 24 nm half pitch resolution at dense C/H, with 0.3NA MET tool.

The continuous studies for both the outgassing reduction and the sensitivity improvement by applying low outgassing photo acid generator with a various kinds of polymer protection group were discussed in this paper. Further reduction of the outgassing segments from the resist was demonstrated to achieve the total outgassing amount below the detection limit of GC-MS (ca. less than 1E+10 molecules / cm 2 ). Loading a large sized acetal group could be successfully reduced the amount of the outgassing segments from polymer below the tool detection limit, which would be acceptable for a high volume manufacturing tool usage. The development properties of PHS based bulky acetal polymers were measured by changing molecular weight. The high dissolution rate contrast was obtained with the bulky acetel protected low molecular weight polymer. A resolution capability study was carried out with micro exposure tool (MET) at LBNL and Albany. The correlation between LWR through CD and DOF was measured by loading various amounts of quencher. The resolution capability of newly developed EUV resist had been successfully improved by modifying both resist polymer matrix and quencher amount optimization. It was possible to obtain 27.7nm lines with MET tool, where LWR value at 35 nm L/S was 3.9 nm with reasonable sensitivity range.

No abstract