Latest results from the SEMATECH Berkeley extreme ultraviolet microfield exposure tool

Microfield exposure tools (METs) continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. One of these tools is the 0.3 numerical aperture SEMATECH Berkeley MET operating as a resist and mask test center. Here they present an update on the tool summarizing some of the latest test and characterization results. they provide an update on the long-term aberration stability of the tool and present line-space imaging in chemically amplified photoresist down to the 20-nm half-pitch level. Although resist development has shown substantial progress in the area of resolution, line-edge-roughness (LER) remains a significant concern. Here we present a summary of recent LER performance results and consider the effect of mask contributors to the LER observed from the SEMATECH Berkeley microfield tool

Double exposure using 193nm negative tone photoresist

ABSTRACT Double exposure is one of the promising methods for extending lithographic patterning into the low k 1 regime. In this paper, we demonstrate double patterning of k 1-effective =0.25 with improved process window using a negative resist. Negative resist (TOK N-series) in combination with a bright field mask is proven to provide a large process window in generating 1:3 = trench:line resist features. By incorporating two etch transfer steps into the hard mask material, frequency doubled patterns could be obtained

Recent results from the Berkeley 0.3-NA microfield exposure tool

Operating as a SEMATECH resist test center, the Berkeley 0.3-NA EUV microfield exposure tool continues to play a crucial role in the advancement of EUV resists and masks. Here we present recent resist-characterization results from the tool as well as tool-characterization data. In particular we present lithographic-based aberration measurements demonstrating the long-term stability of the tool. We also describe a recent upgrade to the tool which involved redesign of the programmable coherence illuminator to provide improved field uniformity as well as a programmable field size