22nm 1:1 line and space patterning by using double patterning and resist reflow process

Abstract

According to ITRS road map, it will be achieved 22 nm half pitch until 2016. However, it is hard to make although EUV, high index immersion. We have positive strategy for 22 nm half pitch with immersion and double patterning and RRP. We can make 22 nm half-pitch with hard mask by using RRP that can shrink trench pattern and double patterning that can get over resolution limitation. Immersion technology can make 44 nm half pitch in NA 1.35. When the developed resist profile can be reflow, so line is increased and space is decreased. It can be 22 nm trench pattern with 66 nm width by using RRP. Hence, we can obtain 66 nm line and 22nm space pattern by etching. And then, we can obtain 22 nm half pitch after doing double patterning. We tried to evaluate this strategy by commercial and home-made simulator.