Resist Reflow Process for 32 nm Node Arbitrary Pattern

Abstract

In order to decrease the size of contact holes, which is usually much larger than other patterns, the resist reflow process (RRP) has been widely used. Various types, shapes, and pitches of contact hole arrays are generated by RRP, but the use of RRP was limited to only contact hole patterns. The use of the same RRP method is expanded to 32 nm node arbitrary and complex patterns including dense line and space patterns. There might be simple one-dimensional patterns, but two-dimensional proximity conflict patterns are difficult to generate in general. In particular, the data split with proximity correction requires much attention for double patterning. 32 nm node arbitrary patterns could be generated using RRP without complex data splits when high-index fluid immersion lithography [numerical aperture (NA) 1.55] is used.