Evaluation of EUV resist materialsfor use at the 32 nm half-pitch node

摘要

The 2007 International Technology Roadmap for Semiconductors (ITRS)1 specifies Extreme Ultraviolet (EUV)lithography as one leading technology option for the 32nm half-pitch node, and significant world wide effort is beingfocused towards this goal. Readiness of EUV photoresists is one of the risk areas. In 2007, the ITRS modifiedperformance targets for high-volume manufacturing EUV resists to better reflect fundamental resist materials challenges.For 32nm half-pitch patterning at EUV, a photospeed range from 5-30 mJ/cm~2and low-frequency linewidth roughnesstarget of 1.7nm (3σ) have been specified. Towards this goal, the joint INVENT activity (AMD, CNSE, IBM, Micron,and Qimonda) at Albany evaluated a broad range of EUV photoresists using the EUV MET at Lawrence BerkeleyNational Laboratories (LBNL), and the EUV interferometer at the Paul Scherrer Institut (PSI), Switzerland. Programgoals targeted resist performance for 32nm and 22nm groundrule development activities, and included interim relaxationof ITRS resist performance targets. This presentation will give an updated review of the results. Progress is evident inall areas of EUV resist patterning, particularly contact/via and ultrathin resist film performance. We also describe asimplified figure-of-merit approach useful for more quantitative assessment of the strengths and weaknesses of currentmaterials.