Kombinierter Reflektor und Filter für Licht underschiedlicher Wellenlängen

Die vorliegende Erfindung betrifft einen Bragg-Reflektor (12) für ein optisches Element einer optischen Anordnung, insbesondere einer Projektionsbelichtungsanlage, mit einer Vielzahl von alternierend angeordneten Schichten (13, 14) mit unterschiedlichem Brechungsindex zur Reflexion von Licht, wobei die Schichten abwechselnd aus einer halbleitenden, binären Verbindung, insbesondere MoP, Ru2Si3 oder YN und Silizium gebildet sind. Außerdem betrifft die Erfindung ein kombiniertes Spiegel- und Filterelement für eine optische Anordnung, insbesondere eine Projektionsbelichtungsanlage, mit einem Substrat (10) und einem auf dem Substrat angeordneten Bragg-Reflektor (12), wie oben beschrieben

RZLINE code modelling of distributed tin targets for laser-produced plasma sources of extreme ultraviolet radiation

Abstract. An integrated model is developed to describe the hydrodynamics, atomic, and radiation processes that take place in extreme ultraviolet (EUV) radiation sources based on a laser-produced plasma with a distributed tin target. The modeling was performed using the RZLINE code—a numerical code for the simulation of EUV emission by hot dense plasmas. The purpose of the simulation is to evaluate the spectral characteristics of the radiation source, conversion efficiency, source size, evaporation rate of the target, energetic, and space distribution of debris (nanoparticles, neutrals, and ions). The advantages of a distributed target in comparison with a single droplet target are also discussed

Comparison of H2 and He carbon cleaning mechanisms in extreme ultraviolet induced and surface wave discharge plasmas

Cleaning of contamination of optical surfaces by amorphous carbon (a-C) is highly relevant for extreme ultraviolet (EUV) lithography. We have studied the mechanisms for a-C removal from a Si surface. By comparing a-C removal in a surface wave discharge (SWD) plasma and an EUV-induced plasma, the cleaning mechanisms of two different gas environments (hydrogen and helium) were determined. The C-atom removal per incident ion was estimated for different sample bias voltages and ion fluxes. It was found that H2 plasmas generally had higher cleaning rates than He plasmas: up to seven times higher for more negatively biased samples in the EUV induced plasma. Moreover, for H2, EUV induced plasma was found to be 2-3 times more efficient at removing carbon than the SWD plasma. It was observed that the carbon removal under exposure to He in both SWD and EUV induced plasmas is due to physical sputtering by He+ ions. In H2, on the other hand, the increase in carbon removal rates, compared to He plasmas, is due to chemical sputtering. The proposed explanation is strengthened by the observation that lower sample temperatures—allowing longer residence times for adsorbed hydrogen species—results in higher cleaning rates. This is a new C cleaning mechanism for EUV-induced plasma, which we call “EUV-reactive ion sputtering.

Infrared suppression by hybrid EUV multilayer-IR etalon structures

We have developed a multilayer mirror for extreme UV (EUV) radiation (13.5nm), which has near-zero reflectance for IR line radiation (10.6 mu m). The EUV reflecting multilayer is based on alternating B(4)C and Si layers. Substantial transparency of these materials with respect to the IR radiation allowed the integration of the multilayer coating in a resonant quarter-wave structure for 10.6 mu m. Samples were manufactured using magnetron sputtering deposition technique and demonstrated suppression of the IR radiation by up to 3 orders of magnitude. The EUV peak reflectance amounts 45% at 13: 5nm, with a bandwidth at FWHM being 0.284 nm. Therefore such a mirror could replace conventional multilayer mirrors to suppress undesired spectral components in monochromatic imaging applications, including EUV photolithography. (C) 2011 Optical Society of Americ

Extreme ultraviolet (EUV) source and ultra-high vacuum chamber for studying EUV-induced processes

An experimental setup that directly reproduces extreme ultraviolet (EUV) lithography relevant conditions for detailed component exposure tests is described. The EUV setup includes a pulsed plasma radiation source, operating at 13.5 nm; a debris mitigation system; collection and filtering optics; and an ultra-high vacuum experimental chamber, equipped with optical and plasma diagnostics. The first results, identifying the physical parameters and evolution of EUV-induced plasmas, are presented. Finally, the applicability and accuracy of the in situ diagnostics is briefly discusse

Infrared suppression by hybrid EUV multilayer - IR lossy etalon structures

Many optical applications demand high reflectivity in a particular wavelength range and, simultaneously, suppression of radiation outside this prime range. Such parasitic radiation can lead to image distortions in imaging applications, or poor signal-noise ratios in spectroscopy. When working with sources of short-wavelength radiation based on laser-produced plasma, suppression of the scattered laser radiation is required. For these purposes we investigated a possibility to integrate an EUV reflecting multilayer coating with a resonant infrared anti-reflecting coating. Pilot samples manufactured with magnetron sputtering demonstrated 3 orders of magnitude suppression of infrared light while still reflecting 45% of the EUV radiation