Pattern defect reduction and LER improvement of chemo-epitaxy DSA process

Directed self-assembly (DSA) has been investigated over the past few years as the candidate for next generation lithography. Especially, sub 20nm line and space patterns obtained by chemo-epitaxy process are expected to apply to DRAM active area, Logic fin and narrow 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 indeed the small pitch walking as a consequence. However, the generating mechanism of the DSA pattern defect is still not cleared 1-4 and the line edge roughness (LER) is not overtaken self- aligned quadruple patterning (SAQP). In this report, we present the latest results regarding the defect reduction and LER improvement work regarding chemoepitaxy line and space pattern. In addition, we introduce the result of application of chemical epitaxy process to hole pattern.