A novel main chain scission type photoresists for EUV lithography

The performance of previous generation material (ZER02#1) were reported at EUVL symposium in 2019. Despite the good performance, the stability issue at development process and the incompatibility of special organic solvents with customer’s Fab requirements led to be difficult its further developments and scaling up. Therefore, Zeon developed a novel ZER02#3 resist by changing monomers and polymer properties in order to keep the EUV adsorption at the same level of ZER02#1 and introduce common organic solvents as developer. The lithographic performance of dense Line-Space (L/S) pattern and of contact holes (C/H) pattern with ZER02#3 resist is presented. For L/S pattern, a resolution of 16 nm half pitch was achieved at the exposure dose of 54.2 mJ/cm², giving a biased LWR of 4.1 nm and a biased LER of 2.6 nm by NXE3300. For hexagonal C/H pattern, 40 nm pitch was resolved at 72.4 mJ/cm², with a LCDU of 3.1 nm by NXE3300. ZER02#3 could enhance sensitivity as keeping lithography performance with ZER02#1. In addition to the enhancement of the lithographic performance achieved, fundamental studies such as Gel Permeation Chromatography were realized to better understand the pattering mechanism under EUV exposure.