Pattern defect reduction for chemo-epitaxy DSA process

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 1-8. Especially, the chemo-epitaxy process has advantages for the sub 20nm line and 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. On the other hand, the chemo-epitaxy process can be applied to the hexagonal close-packed arrangement holes 8. Those holes are expected to be the patterns for DRAM storage. In this paper, the latest results regarding the defect reduction work regarding chemo-epitaxy line and space pattern is reported. Especially, the defect density of the patterns that were transferred to spin on carbon (SOC) film is confirmed.