Holistic litho, films and etch for EUV DRAM storage node pad (Conference Presentation)

Extreme ultraviolet (EUV) lithography is the technology for high volume manufacturing (HVM) of semiconductor ICs for photoresist patterns smaller than 75nm pitch¹. A persistent challenge of the EUV scanner is to supply a high contrast image with enough photons to the photoresist (PR) to meet HVM productivity targets with acceptable dimensional and defectivity control. Local stochastic variability in dimension and placement dominates the total dimension control budget and reducing that variability by increasing the exposure dose comes at the cost of scanner throughput. Our objective is to deliver holistic patterning solutions by co-optimization of patterning film stack, lithography, and subsequent etch processes to transfer the patterns to the target layer with CD and placement control of order 1nm or less! This synergistic approach enables circuit fabrication customers to manage the tradeoff between stochastic defects and productivity in EUV patterning.