Use Of EUV Lithography Research Articles

Study on radiation chemistry of fluorinated polymers for EUV resist

The fluorination of a chemically amplified resist is an effective method for use in EUV lithography. However, it has been suggested that the fluorination of the base polymer of the chemically amplified resist induces the electron scavenging reaction by the base polymer and reduces the acid yield. In this study, we clarified the formation of transient species and the acid yields of fluorinated polymers after exposure to the ionizing radiations. The acid yields of fluorinated polymers with hydroxyl groups were lower than that of poly(4-hydroxystyrene) (PHS). The lower acid generation efficiency in fluorinated polymers was due to not only the reaction between fluorinated polymers and electrons but also the lower deprotonation efficiency of the radical cation of the fluorinated polymer.

Fluorine-Stabilized Acid Amplifiers for Use in EUV Lithography

Fluorine-Stabilized Acid Amplifiers for Use in EUV Lithography

Status of EUV lithography at IMEC

IMEC has started an EUV lithography research program based on ASMLs EUV full field scanner, the Alpha Demo Tool (ADT). The intent of this program is to help improve and establish the necessary mask and resist infrastructure, and achieve learning to prepare for the use of EUV lithography in future production of integrated circuits. The program focuses on three main projects: EUV resists, EUV reticles and assessment of the ADT performance. In this paper, the status and the progress of each of the projects is reviewed. In preparation for a resist process for the ADT, interference lithography has been used to track the progress of resist performance. Good progress in resist performance is illustrated by the ability of some materials to resolve 25nm HP. In its initial phase, the reticle project has concentrated on working with the mask and blank suppliers to assure timely availability of reticles for the ADT. An overview is given of reticle related activities, as well as first results of a defect printability study by simulation. In the ADT assessment project, simulation studies are reported aimed at the development of optical correction for flare and reticle shadowing effects. The impact of flare and shadowing effects are well understood and strategies for flare mitigation and shadowing effect correction are proposed.