Blister formation in Mo/Si multilayered structures induced by hydrogen ions
TL;DR: In this paper, the influence of hydrogen flux and ion energy for blister formation in nanometer thick Mo/Si multilayer structures due to exposure to hydrogen ion fluxes was measured and compared to a blister model.
Abstract: We report on blister formation in nanometer thick Mo/Si multilayer structures due to exposure to hydrogen ion fluxes The influence of hydrogen flux and ion energy for blister formation have been measured and compared to a blister model The blister number density increases significantly around 100 eV when increasing the ion energy from 50 to 200 eV This stepwise behavior could be explained by the fact that for energies >100 eV hydrogen ions could directly penetrate to the depth where delamination takes place From the blister model also the blisters internal pressure and surface energy was calculated to be around 100–800 MPa and respectively
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TL;DR: In this paper, the authors reported on the measurements of ion flux composition and ion energy distribution functions (IEDFs) at surfaces in contact with hydrogen plasmas induced by extreme ultraviolet (EUV) radiation.
Abstract: This work reports on the measurements of ion flux composition and ion energy distribution functions (IEDFs) at surfaces in contact with hydrogen plasmas induced by extreme ultraviolet (EUV) radiation. This special type of plasma is gaining interest from industries because of its appearance in extreme ultraviolet lithography tools, where it affects exposed surfaces. The studied plasma is induced in 5 Pa hydrogen gas by irradiating the gas with short (30 ns) pulses of EUV radiation ( λ= 10–20 nm). Due to the low duty cycle (10–4), the plasma is highly transient. The composition and IEDF are measured using an energy resolved ion mass spectrometer. The total ion flux consists of H+, H2+, and H3+. H3+ is the dominant ion as a result of the efficient conversion of H2+ to H3+ upon collision with background hydrogen molecules. The IEDFs of H2+ and H3+ appear similar, showing a broad distribution with a cut-off energy at approximately 8 eV. In contrast, the IEDF of H+ shows an energetic tail up to 18 eV. Most probably, the ions in this tail gain their energy during their creation process by photoionization and dissociative electron impact ionization.
44 citations
TL;DR: In this paper, an overview of the existing knowledge regarding EUV-induced plasmas characteristics is provided, which describes common, as well as distinguishing, features of it in comparison with other Plasmas and discusses its interaction with solid materials.
Abstract: After a long period of relatively low interest, science related to effects in the Extreme Ultraviolet (EUV) spectrum range experienced an explosive boom of publications in the last decades A new application of EUV in lithography was the reason for such a growth Naturally, an intensive development in such area produces a snowball effect of relatively uncharted phenomena EUV-induced plasma is one of those While being produced in the volume of a rarefied gas, it has a direct impact onto optical surfaces and construction materials of lithography machines, and thus has not only scientific peculiarity, but it is also of major interest for the technological application The current article provides an overview of the existing knowledge regarding EUV-induced plasma characteristics It describes common, as well as distinguishing, features of it in comparison with other plasmas and discusses its interaction with solid materials This article will also identify the gaps in the existing knowledge and it will propose ways to bridge them
42 citations
Cites background from "Blister formation in Mo/Si multilay..."
...Delamination in Mo/Si multilayer samples due to ion irradiation has been experimentally confirmed using moderate energy (50–200 eV) [96,97] and energetic (>800 eV) hydrogen ions [95,98]....
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...Thus far, delamination studies have been focusing on ion-surface interactions where ion fluxes were generated while using alternative sources, like thermal gas crackers [94,95] or an ion gun [96]....
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TL;DR: In this paper, a review of recent advances in the minimum-destructive testing of the adhesion of coating-substrate systems are reviewed, focusing on key techniques such as micro-and nano-scale levels of indentation, scratching, laser-induced wave shock, as well as the blister and buckle approach.
30 citations
TL;DR: In this article, a diagnostic approach using multi-mode microwave cavity resonance spectroscopy (MCRS) is introduced to determine electron dynamics non-invasively in an absolute sense, as a function of time and spatially resolved.
Abstract: A new diagnostic approach using multi-mode microwave cavity resonance spectroscopy (MCRS) is introduced. This can be used to determine electron dynamics non-invasively in an absolute sense, as a function of time and spatially resolved. Using this approach, we have for the first time fully mapped electron dynamics specifically during the creation and decay of a highly transient pulsed plasma induced by irradiating a background gas with extreme ultraviolet (EUV) photons. In cylindrical geometry, electron densities as low as 1012 m−3 could be detected with a spatial resolution of (sub)100 µm and a temporal resolution of (sub)100 ns. Our experiments clearly show production of electrons even after the in-band EUV irradiation fades out. This phenomenon can be explained by both photoionization by out-of-band EUV radiation emitted by the EUV source later in time and delayed electron impact ionization by electrons initially created by in-band EUV photoionization. From the analysis, the absolute width of the electron cloud in the probing volume could also be retrieved temporally resolved. This data clearly indicates cooling of electrons. From an application perspective, it is demonstrated that the method can be used as a non-invasive and in-line monitor for ionizing radiation in terms of beam power, profile and pointing stability.
24 citations
TL;DR: In this article, an overview of current mirror technology for space missions with a focus on the importance of the degradation and radiation resistance of coating materials is presented. And special attention is given to degradation effects on mirrors for far and extreme UV, as in these ranges the degradation is enhanced by the strong absorption of most contaminants.
Abstract: Mirrors are a subset of optical components essential for the success of current and future space missions. Most of the telescopes for space programs ranging from earth observation to astrophysics and covering the whole electromagnetic spectrum from x-rays to far-infrared are based on reflective optics. Mirrors operate in diverse and harsh environments that range from low-earth orbit to interplanetary orbits and deep space. The operational life of space observatories spans from minutes (sounding rockets) to decades (large observatories), and the performance of the mirrors within the mission lifetime is susceptible to degrading, resulting in a drop in the instrument throughput, which in turn affects the scientific return. Therefore, the knowledge of potential degradation mechanisms, how they affect mirror performance, and how to prevent them is of paramount importance to ensure the long-term success of space telescopes. In this review, we report an overview of current mirror technology for space missions with a focus on the importance of the degradation and radiation resistance of coating materials. Special attention is given to degradation effects on mirrors for far and extreme UV, as in these ranges the degradation is enhanced by the strong absorption of most contaminants.
19 citations
References
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TL;DR: In this article, the authors describe the mixed mode cracking in layered materials and elaborates some of the basic results on the characterization of crack tip fields and on the specification of interface toughness, showing that cracks in brittle, isotropic, homogeneous materials propagate such that pure mode I conditions are maintained at the crack tip.
Abstract: Publisher Summary This chapter describes the mixed mode cracking in layered materials. There is ample experimental evidence that cracks in brittle, isotropic, homogeneous materials propagate such that pure mode I conditions are maintained at the crack tip. An unloaded crack subsequently subject to a combination of modes I and II will initiate growth by kinking in such a direction that the advancing tip is in mode I. The chapter also elaborates some of the basic results on the characterization of crack tip fields and on the specification of interface toughness. The competition between crack advance within the interface and kinking out of the interface depends on the relative toughness of the interface to that of the adjoining material. The interface stress intensity factors play precisely the same role as their counterparts in elastic fracture mechanics for homogeneous, isotropic solids. When an interface between a bimaterial system is actually a very thin layer of a third phase, the details of the cracking morphology in the thin interface layer can also play a role in determining the mixed mode toughness. The elasticity solutions for cracks in multilayers are also elaborated.
3,828 citations
TL;DR: In this article, the tensile and compressive behavior of -oriented body-centered cubic (bcc) metals W, Mo, Ta and Nb with nanometer dimensions was investigated.
309 citations
TL;DR: In this paper, a study of delamination at the interface between a thin elastic film bonded to a substrate under conditions in which the film is subject to equi-biaxial compression is presented.
Abstract: A study is presented of delamination at the interface between a thin elastic film bonded to a substrate under conditions in which the film is subject to equi-biaxial compression. The focus is on initially circular delaminations. When the initial delamination is sufficiently large it buckles away from the substrate producing a blister which in turn induces a driving force on the interface crack tip. A two-part theoretical analysis of the coupled buckling/fracture problem is conducted: the axisymmetric growth of the circular blister, and the stability of the circular blister to nonaxisymmetric perturbations of the interface crack front. A simple criterion is identified which excludes the possibility of wide-spread delamination. Experiments are reported for a model film/substrate system (mica bonded to aluminum) chosen to allow visualization of the interface and to permit compressive stresses in the film to be generated over the full range of interest by exploiting the large thermal expansion mismatch of the system. The experiments bear out the theoretical prediction of a regime of axisymmetric growth which gives way to nonaxisymmetric blisters after a blister becomes sufficiently large. The study suggests that the wavy-circular and worm-like blister morphologies which are usually observed for delaminated films are a manifestation of the configurational instability of the interface crack front.
281 citations
TL;DR: In this paper, a review of hydrogen bubble formation in metals is presented, focusing on those areas of bubble formation where the distinct chemical character of hydrogen is important, and a distinction is made between nucleation and subsequent cavity growth mechanisms.
268 citations
TL;DR: In this article, the compressibility isotherms of hydrogen and deuterium were given in the following ranges of temperatures, densities, and pressures: hydrogen at temperatures from 175C to 25C and at densities up to 640 Amagat (maximum pressure about 1000 atmospheres) ; at temperatures ranging from 0C to 150C, and densities at density up to 960 amagat, and maximum pressure about 2950 atmospheres.
159 citations