No abstract

No abstract

The volume, index-of-refraction, and stress changes induced in vitreous silica by irradiating with 18-keV electrons have been measured over the dose range from 2.5×1010 to 3×1012 rad. The volume and index measurements were performed using a new technique based on producing a spatial modulation of irradiated and unirradiated areas which is used as an optical phase grating. Comparison of the volume change and stress measurements shows there are two components to the compaction; one component, which dominates below doses of 2×1011 rad, is associated with stress generation, while the other component, which dominates at higher doses, proceeds without generating stress. In addition, the relationship between the index change and volume change observed for electron irradiation is different from that obtained by neutron irradiation and hydrostatic compression. The index-vs-volume change data can be interpreted using the Lorentz-Lorenz formalism and Neuman strain-optical constants, and provides further evidence of the two different compaction processes. The measured stress saturates at 1.5×108 N/m2 at approximately 6×1011 rad (0.24% volume change) and decreases with subsequent irradiation. In contrast the volume and index changes saturate at approximately 2×1012 rad (1.4% volume change).

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 1 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 fullfield 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.

No abstract