Defect mitigation of chemo-epitaxy DSA patterns

Directed self-assembly (DSA) is one of the candidates for next generation lithography. Over the past years, many papers and presentation have been reported regarding DSA, and Tokyo Electron Limited (TEL is a registered trademark or a trademark of Tokyo Electron Limited in Japan and /or other countries.) also has presented the evaluation results and the advantages of each^1-9. Especially, the chemo-epitaxy process has advantages for the sub 20nm line & space patterns to apply to active area patterns for DRAM, fin patterns for Logic and narrow pitch of metal patterns. One of the biggest advantages of DSA lines is that the pattern pitch is decided by the specific factors of the block copolymer, and it achieves the small pitch walking as a consequence. In this paper, the latest results regarding the defect reduction work regarding chemo-epitaxy line & space pattern is reported. And, sub-10nm process flow without using high-chi BCP is discussed.