<title>System integration and performance of the EUV engineering test stand</title>

TLDR

The Engineering Test Stand (ETS) is a developmental lithography tool aimed at demonstrating full‑field EUV imaging and supplying data for commercial tool development. The ETS employs a 4‑mirror, 4×‑reduction, ring‑field projection system with a 0.1 numerical aperture, 70 nm resolution at k1 = 0.52, illuminated by 13.4 nm laser‑produced plasma directed onto an arc‑shaped field, and uses vacuum‑compatible, magnetically levitated scanning stages for full‑field step‑and‑scan imaging. System performance during the first integration phase included static resist images of 100 nm isolated and dense features.

Abstract

The Engineering Test Stand (ETS) is a developmental lithography tool designed to demonstrate full-field EUV imaging and provide data for commercial-tool development. In the first phase of integration, currently in progress, the ETS is configured using a developmental projection system, while fabrication of an improved projection system proceeds in parallel. The optics in the second projection system have been fabricated to tighter specifications for improved resolution and reduced flare. The projection system is a 4-mirror, 4x-reduction, ring-field design having a numeral aperture of 0.1, which supports 70 nm resolution at a k<SUB>1</SUB> of 0.52. The illuminator produces 13.4 nm radiation from a laser-produced plasma, directs the radiation onto an arc-shaped field of view, and provides an effective fill factor at the pupil plane of 0.7. The ETS is designed for full-field images in step-and-scan mode using vacuum-compatible, magnetically levitated, scanning stages. This paper describes system performance observed during the first phase of integration, including static resist images of 100 nm isolated and dense features.