Previously, fundamental evaluations of the Extreme Ultra Violet (EUV) lithography process have been conducted using the CLEAN TRACK ACT™ 12 coater/developer with the ASML EUV Alpha Demo Tool (ADT) at imec. [1] [2] In that work, we confirmed the basic process sensitivities for the critical dimension (CD) and defectivity with EUV resists. Ultimate resolution improvements were examined with TBAH and FIRM™ Extreme. Moving forward with this work, the latest inline cluster is evaluated using the ASML NXE:3100 pre-production EUV scanner and the CLEAN TRACK™ LITHIUS Pro™ -EUV coater/developer. The imec standard EUV baseline process has been evaluated for manufacturability of CD uniformity control based on half pitch (HP) 27nm and ultimate resolution studies focusing on HP 22nm. With regards to the progress of the improvement for EUV processing, we confirmed the effectiveness of several novel concepts: FIRM™ Extreme10 showed increase in ultimate resolution and improvement in line width roughness (LWR) and process window; Tokyo Electron LTD. (TEL) smoothing process for roughness reduction showed 17% improvement for line and space (L/S) patterns; and finally the new dispense method reduced patterned wafer defectivity by over 50%.
As Extreme ultraviolet (EUV) lithography technology shows promising results below 40nm feature sizes, TOKYO ELECTRON LTD.(TEL) is committed to understanding the fundamentals needed to improve our technology, thereby enabling customers to meet roadmap expectations. TEL continues collaboration with imec for evaluation of Coater/Developer processing sensitivities using the ASML Alpha Demo Tool for EUV exposures. The results from the collaboration help develop the necessary hardware for EUV Coater/Developer processing. In previous work 1 , processing sensitivities of the resist materials were investigated to determine the impact on critical dimension (CD) uniformity and defectivity. In this work, new promising resist materials have been studied and more information pertaining to EUV exposures was obtained. Specifically, post exposure bake (PEB) impact to CD is studied in addition to dissolution characteristics and resist material hydrophobicity. Additionally, initial results show the current status of CDU and defectivity with the ADT/CLEAN TRACK ACT™12 lithocluster. Analysis of a five wafer batch of CDU wafers shows within wafer and wafer to wafer contribution from track processing. A pareto of a patterned wafer defectivity test gives initial insight into the process defects with the current processing conditions. From analysis of these data, it's shown that while improvements in processing are certainly possible, the initial results indicate a manufacturable process for EUV.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.