Study of the beam blur and its effect on the future mask fabrication

For the half pitch below 45nm, the required sub-resolution feature size is about to be 60nm, and the uniformity of dense lines to be below 3.4nm for the mask fabrication. To achieve this requirement, the reduction of beam blur is necessary. On the mask patterning using 50keV electron beam, the beam blurring due to coulomb interaction and resist characteristics is the main effect of the pattern image degradation and the limit of CD uniformity. In this report, we present the effect of the beam blur induced by coulomb interaction and resist. And we report the recent simulated and experimental results on the resolution change depending on bream blur and design node. Finally, we conclude that the reduction of beam blur can improve the mask quality and there is a compatible condition between the beam blur and the mask fabrication.