As the process node becomes more advanced, the accuracy and precision in OPC pattern CD are required in mask
manufacturing. CD SEM is an essential tool to confirm the mask quality such as CD control, CD uniformity and CD
mean to target (MTT).
Unfortunately, in some cases of arbitrary enclosed patterns or aggressive OPC patterns, for instance, line with tiny
jogs and curvilinear SRAF, CD variation depending on region of interest (ROI) is a very serious problem in mask CD
control, even it decreases the wafer yield. For overcoming this situation, the 2-dimensional (2D) method by Holon is
adopted. In this paper, we summarize the comparisons of error budget between conventional (1D) and 2D data using CD
SEM and the CD performance between mask and wafer by complex OPC patterns including ILT features.