A new mask exposure and analysis facility

Abstract

The introduction of ever higher source powers in EUV systems causes increased risks for contamination and degradation of EUV masks and pellicles. Appropriate testing can help to inventory and mitigate these risks. To this end, we propose EBL2: a laboratory EUV exposure system capable of operating at high EUV powers and intensities, and capable of exposing and analyzing EUV masks. The proposed system architecture is similar to the EBL system which has been operated jointly by TNO and Carl Zeiss SMT since 2005. EBL2 contains an EUV Beam Line, in which samples can be exposed to EUV irradiation in a controlled environment. Attached to this Beam Line is an XPS system, which can be reached from the Beam Line via an in-vacuum transfer system. This enables surface analysis of exposed masks without breaking vacuum. Automated handling with dual pods is foreseen so that exposed EUV masks will still be usable in EUV lithography tools to assess the imaging impact of the exposure. Compared to the existing system, large improvements in EUV power, intensity, reliability, and flexibility are proposed. Also, in-situ measurements by e.g. ellipsometry is foreseen for real time monitoring of the sample condition. The system shall be equipped with additional ports for EUVR or other analysis tools. This unique facility will be open for external customers and other research groups.

First light and results on EBL2

“…The concept study was described in Ref. [3] . The system was realized in close collaboration with our technology partners Ushio Inc for the Sn fueled DPP EUV source and ASYS Automatic Systems GmbH & Co. KG for both the vacuum and atmospheric handler.…”

EBL2, a flexible, controlled EUV exposure and surface analysis facility

“…The concept study was described in Ref. [2]. The present paper gives an overview of the EBL 2 system design, and provides more detailed information on accepted samples, the sample handling system and XPS modules.…”