State-of-the-art of EUV materials for N5 logic and DRAM applications

In the last year, the continuous efforts on the development of extreme ultraviolet lithography (EUVL) has allowed to push the lithographic performance of the EUV photoresists on the ASML NXE:3300 full field exposure tool. However, EUVL materials are deemed as critical to enable and extend the EUV lithography technology in a cost-effective manner. In this work, we present the imec activity on EUV materials. We show the results of the best performing EUV photoresists for dense line-space pattern at 32nm pitch, dense contact holes at 36nm pitch and dense staggered pillars at Px70nm-Py40nm pitch, reporting the most critical patterning challenges for the investigated structures. We discuss manufacturing challenges as nano-failures, line-width roughness, local critical dimension (CD) uniformity, process window limitations and metal cross contamination of metal containing resist (MCR). Further, we discuss the role of the substrate underneath the EUV photoresist and alternative patterning solutions as the tone reversal process (TRP). Furthermore, we discuss novel EUV materials lain on the horizon and fundamental material aspects.