Anisotropic resist reflow process simulation for 22 nm elongated contact holes

Pattern size decreases as circuit integration increases. Resistance increases as the cross section of a contact hole (CH) decreases. Thus, the use of an elongated CH is suggested as a method of solving this problem. It is too difficult to obtain a small CH and an elongated CH by optical proximity correction only. Even if double patterning can be used to improve the integration of line and space, it is not easy to apply it to form an elongated CH. We suggest the use of a resist reflow process method to form 22 nm elongated CHs from a large developed size pattern. We observed RRP behavior in elongated CHs by experiment and simulation, and applied optical proximity correction to compensate the bulk effect after the resist reflow process. As a result, we made uniform 22 nm elongated CHs