Novel scanner corrections for co-optimizing imaging and overlay to enable critical EUV and DUV lithography after wafer-to-wafer bonding

This paper addresses the increasing need for stringent overlay and imaging control in semiconductor manufacturing, driven by wafer-to-wafer bonding - advanced 3D integration, in both logic and memory segments. We present novel scanner correction methods for co-optimizing overlay and imaging, targeting much larger overlay correction requests with higher spatial frequency. These innovations in scanner control deliver the required on-product patterning performance and yield for next-generation semiconductor devices. In this paper we present the results of this optimization using an experimental test use case. The experiment is conducted using 0.33 EUV lithography scanner. The imaging test vehicle is designed to assess the effect of overlay corrections on LCDU (Local Critical Dimension Uniformity) imaging performance. The test reticle featured a 20nm contact hole pattern with a 40nm pitch. LCDU performance in resist was measured based on representative field correction from wafer bonding. The results indicate that increasing the emphasis on fading for scanner control yields a substantial improvement in LCDU, as scanner trajectories are optimized to mitigate fading parasitic effects. LCDU measurements showed ~0.5-nm enhancement.