Progress in EUV Underlayer Materials

Abstract

EUV lithography continues to be developed as a technology for sub-30nm and especially sub-20nm pattern imaging in the semiconductor industry. To achieve the desired photoresist resolution, line width roughness and sensitivity (RLS) performance for such fine feature patterns, multilayer materials are almost certainly needed to define the overall lithography process. EUV underlayer (EBL) materials with high EUV photon absorption (EPA) unit can improve resist performance in areas such as sensitivity, imaging capability, dissolution contrast, resolution and process window. In this paper, we report more detailed studies on our new generation of EBL materials, showing enhanced integrated EUV performance including reduction of LWR. One advanced EBL material tested has incorporated metal components, and shows sensitivity improvement as well as high etch selectivity, and can be used as hard mask for next generation pattern imaging.