Quantification of SAQP process variation by using hybrid e-beam metrology

This study investigates a hybrid metrology approach for quantifying profile variations in the SAQP (Self-Aligned Quadruple Patterning) process. By comparing CD-SEM measurements with FIB cross-sectional data, the method enables enhanced 3D metrology capabilities beyond conventional top-view CD measurements. Line top rounding and substrate loss in SAQP structures were quantitatively extracted from CD-SEM profile data, with FIB cross-sectional analysis used to confirm and refine the results. This approach supports accurate 3D profile characterization for evaluating etch-induced variations. The application of this hybrid e-beam metrology during the device development phase enables early definition of monitoring indicators for high-volume manufacturing, potentially contributing to reduced turnaround time (TAT) through faster process feedback and improved process control.