&lt;title&gt;Prevention of MoSi multilayer reflection loss in EUVL tools&lt;/title&gt;

Meiling, H.; Mertens, Bas; Stietz, F.; Wedowski, Marco; Klein, R.; Kurt, R.; Louis, Eric; Yakshin, Andrey

doi:10.1117/12.450949

Cited by 20 publications

(21 citation statements)

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“…Design considerations and results on individual mirrors have been published previously [1][2][3][4][5][6]. The MSFR achieved on the six mirrors of the POB leads to a flare level of 23% on system level.…”

Section: Setup Pobmentioning

confidence: 95%

“…As described previously [2][3][4][5][6] the ASML EUV AD-tool consists of multiple separate vacuum compartments, each optimized for ease of maintenance and operation. The vacuum level in the main chamber -which holds the illumination system, the reticle stage, and the projection optics -is one of the key drivers to mitigate contamination of the optical system.…”

Section: Overviewmentioning

confidence: 99%

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First performance results of the ASML alpha demo tool

et al. 2006

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The ASML EUV alpha demo tool is operational! The alpha demo tool is a 0.25NA fully functional lithography tool with a field size of 26 33 mm 2 , enabling process development at the 40-nm technology node. In this paper we describe the tool performance, show that vacuum is achieved in a few hours, and demonstrate that our optics contamination strategy mitigates degradation of the optics. Additional data shows the Sn source cost-of-ownership to be comparable to state-of-the-art ArF source systems, by implementing a collector contamination mitigation strategy that includes cleaning. And, we present our first 35-nm dense lines and spaces (half pitch) resist images.

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Section: Setup Pobmentioning

confidence: 95%

Section: Overviewmentioning

confidence: 99%

First performance results of the ASML alpha demo tool

et al. 2006

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“…Silicon is a material that is widely used as the top layer in multilayer EUV optics that easily oxidizes on the surface leading to the growth of oxide layers upon EUV radiation [2][3][4]. During the oxidation process, adsorbed water molecules are dissociated by secondary electrons from the incident EUV radiation and the oxygen atoms react with the Si surface to create SiO 2 [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…In general, two primary reactive threats contribute to a loss of EUV mirror reflectivity: (1) growth of a carbonaceous layer on the mirror surface caused by the EUV induced dissociation of adsorbed hydrocarbons; and (2) oxidation of the mirror surface by the radiative dissociation of adsorbed water [1][2][3][4]. Whether an optic is oxidized or carbonized in a given environment depends in part on the relative amounts of H 2 O and hydrocarbon in the gas-phase environment.…”

Section: Introductionmentioning

confidence: 99%

Gas phase study of the reactivity of optical coating materials with hydrocarbons using a desk-top size EUV laser

et al. 2008

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The reactivity of prospective capping layer extreme ultraviolet (EUV) mirror materials with hydrocarbons, alcohols, and water is studied in the gas phase using mass spectroscopy of metal-oxide clusters. We report the results of chemistry studies for Si, Ti, Hf, Zr, and Ru metal oxide nanoclusters in which the reaction products were ionized with little or no fragmentation by 26.5 eV photons from a desk-top size 46.9 nm Ne-like Ar laser. Hf and Zr oxides are found to be much less reactive than Si or Ti oxides in the presence EUV light. Ru oxides show different chemistry and are inactive with water/alcohols, and active with saturated/unsaturated hydrocarbons. The results are relevant to the design of EUV mirror capping layers that are resistant to carbon contamination.

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“…The practical usability of such optics depends on their lifetime, which can be reduced by several degradation processes [95][96][97][98][99]. In particular, we distinguish degradation due to surface phenomena and internal changes to the ML structure.…”

Section: Introductionmentioning

confidence: 99%

Single-order lamellar multilayer gratings

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Cover: 3D artist impression of a Lamellar Multilayer Grating (LMG). A Transmission Electron Microscope image of an actual LMG is shown on the rear. The grating was etched into a 400 bi-layer W/Si multilayer mirror with a total stack height H of 1 μm and a tungsten layer thickness of only 3 atoms. The grating had a period D of 300 nm and a lamel width ΓD of 75 nm. In comparison to the TEM image on the rear, the red and green layers in the artist impression correspond to tungsten and silicon, respectively. The bi-layer period in the artist impression is overestimated by a factor of 10 for visibility. SummaryA major challenge in the soft x-ray (SXR) and eXtreme UltraViolet (XUV) spectral ranges is the ability to manipulate the incident radiation using optical elements. By patterning conventional multilayer mirrors with nanoscale structures, novel optical elements with a variety of optical properties can be obtained. In this work, the design, fabrication and characterization of Lamellar Multilayer Gratings (LMG) was investigated. Such LMGs are a particular form of the general class of Bragg-Fresnel optics which combine Fresnel optics with Bragg reflection to provide unique dispersive and focusing optics. In particular, LMGs can be used to improve the spectral resolution of x-ray fluorescence techniques.A Coupled Waves Approach (CWA) was derived to simulate the optical performance, in terms of resolution and reflectivity, of LMGs. This CWA allowed to study the physical principles behind LMGs and resulted in the identification of an optimal LMG operating regime. In this regime, the incident beam is reflected in a single diffraction order and is hence referred to as the singleorder regime. Such single-order LMGs were fabricated using UV-NanoImprint Lithography and Bosch Deep Reactive Ion Etching, a process chosen to enable rapid practical development. Single-order operation was experimentally demonstrated and showed an improvement in spectral resolution of a factor of 3.8 with regard to conventional multilayer mirrors. Singe-order excitation of higher diffraction orders was also measured and analyzed.Single-order operation often requires multilayer stacks and grating structures that cannot be fabricated with sufficient accuracy using current technologies. As this invalidates the semi-infinite multilayer approximation, we investigated the optical performance of LMGs with finite multilayer stacks. We determined the ratio between the absorber thickness and bi-layer period of the multilayer stack can be used to further tailor LMG optical performance to maximize bandwidth reduction or minimize peak reflectivity loss. We also investigated various degradation processes that could limit the lifetime of LMGs, which is important for the applicability of such elements. Oxidation of tungsten and silicon as well as changes to the sidewall composition were clearly seen. However, SXR reflectivity remained stable to within measurement accuracy for an extended storage period of 18 months in a 1 atm air environment. The possibility of ...

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<title>Prevention of MoSi multilayer reflection loss in EUVL tools</title>

Cited by 20 publications

References 0 publications

First performance results of the ASML alpha demo tool

First performance results of the ASML alpha demo tool

Gas phase study of the reactivity of optical coating materials with hydrocarbons using a desk-top size EUV laser

Single-order lamellar multilayer gratings

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