Leonard E. Klebanoff

Leonard E. Klebanoff
Sandia National Laboratories · Hydrogen Combustion Technologies

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112
Publications
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Publications

Publications (112)
Article
We report modeling results for hydrogen releases associated with deploying hydrogen fuel cell technology on vessels. This first paper (I) considers hydrogen releases through the vessel Vent Mast from 250-bar hydrogen gas storage tanks, the type of tanks being used for the first hydrogen vessels. A manifolded 10-tank hydrogen storage system, holding...
Article
Results are presented for computational fluid dynamics (CFD) modeling for varying hydrogen leaks within a hydrogen vessel's Fuel Cell Rack inside a Fuel Cell Room. In the limiting case of no room ventilation, modeling shows that the flammable region produced by the hydrogen leak is initially limited by self-induced entrainment and recirculation of...
Article
Solid-state hydrogen storage materials often operate via transient, multistep chemical reactions at complex interfaces that are difficult to capture. Here, we use direct ab initio molecular dynamics simulations at accelerated temperatures and hydrogen pressures to probe the hydrogenation chemistry of the candidate material MgB2 without a priori ass...
Article
The Scripps Institution of Oceanography (SIO) current coastal/local research vessel, the R/V Robert Gordon Sproul, is nearing the end of its service life and will soon require replacement. This study compares three potential variants for an R/V Sproul replacement vessel (SRV): a Baseline SRV consisting of a traditional diesel-electric powertrain, a...
Article
Mg(BH4)2 is an attractive hydrogen storage material, owing to its high gravimetric capacity of 14.9 wt %. However, the dehydrogenated material MgB2 is very difficult to rehydrogenate, requiring excessive pressures and temperatures. Here we report the influence of LiH and TiH2 on hydrogen storage reactions involving Bulk MgB2 using XRD, XAS, FTIR an...
Article
Two-dimensional (2D) metal-boride-derived nanostructures have been a focus of intense research for the past decade, with an emphasis on new synthetic approaches, as well as on the exploration of possible applications in next-generation advanced materials and devices. Their unusual mechanical, electronic, optical, and chemical properties, arising fr...
Article
Metal borides have attracted the attention of researchers due to their useful physical properties and unique ability to form high hydrogen-capacity metal borohydrides. We demonstrate improved hydrogen storage properties of a nanoscale Mg-B material made by surfactant ball milling MgB2 in a mixture of heptane, oleic acid and oleylamine. TEM data sho...
Article
A study is presented to determine the technical, regulatory, and economic feasibility of a coastal research vessel (named the “Zero-V”) powered solely by hydrogen fuel cells. Feasibility is examined in the context of science mission profiles of particular significance in coastal oceanography that require a modern, capable, general-purpose coastal r...
Article
An investigation is reported of possible kinetic limitations to MgB2 hydrogenation. The role of H–H bond breaking, a necessary first step in the hydrogenation process, is assessed for bulk MgB2, ball-milled MgB2, as well as MgB2 mixed with Pd, Fe and TiF3 additives. The Pd and Fe additives in the MgB2 material exist as dispersed metallic particles...
Article
Predictions are made for the radiation-induced carbon contamination threat to ruthenium-coated extreme ultraviolet (EUV) optics for a range of incident EUV intensities, exposure pressures and types of hydrocarbon. A calculational philosophy is developed that acknowledges the ruthenium capping layer may have adsorbed oxygen on it and that the carbon...
Article
TiCl3 and TiF3 additives are known to facilitate hydrogenation and dehydrogenation in a variety of hydrogen storage materials, yet the associated mechanism remains under debate. Here, experimental and computational studies are reported for the reactivity with hydrogen gas of bulk and ball-milled TiCl3 and TiF3 at the temperatures and pressures for...
Article
A theoretical comparison is made of the “well to waves” (WTW) greenhouse gas (GHG) and criteria pollutant emissions from the SF-BREEZE high-speed hydrogen PEM fuel cell ferry and the VALLEJO ferry powered by traditional diesel engine technology but constrained to Tier 4 emissions standards. The emissions were calculated for a common maritime missio...
Article
Internal interfaces in the Li3N/[LiNH2 + 2LiH] solid-state hydrogen storage system alter the hydrogenation and dehydrogenation reaction pathways upon nanosizing, suppressing undesirable intermediate phases to dramatically improve kinetics and reversibility. The key role of solid interfaces in determining thermodynamics and kinetics suggests a new p...
Article
Nucleation of intermediate phases can severely limit the kinetics of solid-state hydrogen storage reactions in complex metal hydrides. In article number 1600803, Brandon Wood and co-workers combine experiment and theory to show how nanoconfinement can suppress intermediates in the Li3N/[LiNH2 + 2 LiH] system to dramatically improve performance. Thi...
Article
We review liquid hydrogen (LH2) as a maritime vessel fuel, from descriptions of its fundamental properties to its practical application and safety aspects, in the context of the San Francisco Bay Renewable Energy Electric Vessel with Zero Emissions (SF-BREEZE) high-speed fuel-cell ferry. Since marine regulations have been formulated to cover liquid...
Article
The structure-dependent vibrational properties of different Mg(BH4)2 polymorphs (α, β, γ, and δ phases) were investigated with a combination of neutron vibrational spectroscopy (NVS) measurements and density functional theory (DFT) calculations, with emphasis placed on the effects of local structure and orientation of the BH4-anions. DFT simulation...
Article
An analysis is presented of a method to protect the reticle (mask) in an extreme ultraviolet (EUV) mask inspection tool using a showerhead plenum to provide a continuous flow of clean gas over the surface of a reticle. The reticle is suspended in an inverted fashion (face down) within a stage/holder that moves back and forth over the showerhead ple...
Article
Model calculations are presented for thermophoretic protection of an extreme ultraviolet (EUV) mask placed face down in an EUV mask inspection tool. The protection factors, defined as the ratio of challenge particles to deposited particles, are calculated for a variety of test conditions (temperature gradient, gas type, particle density, and partic...
Article
Accepted Author Version. Not yet edited or proofed. Please see disclaimer on the article abstract page.
Article
This study examines the practical prospects and benefits for using interstitial metal hydride hydrogen storage in “unsupported” fuel cell mobile construction equipment and aviation GSE applications. An engineering design and performance study is reported of a fuel cell mobile light tower that incorporates a 5 kW Altergy Systems fuel cell, Grote Tri...
Article
We report the results of a project aimed to introduce proton exchange membrane (PEM) hydrogen fuel cell technology into aviation ground support equipment (GSE) and rental construction equipment. The purpose of the project was to design, build, field-test and then commercialize fuel cell equipment that is superior to its diesel counterpart. The comm...
Article
We report a study of the hydrogen storage properties of materials that result from ball milling Ca(BH4)2 and MNH2 (M = Li or Na) in a 1:1 molar ratio. The reaction products were examined experimentally by powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), simultaneous thermogravimetric modulated be...
Article
We report a study of the hydrogen storage properties of materials that result from ball milling Ca(BH4)(2) and MNH2 (M = Li or Na) in a 1:1 molar ratio. The reaction products were examined experimentally by powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), simultaneous thermogravimetric modulated...
Article
Fuel cell systems have the potential to provide high-efficiency, low-cost power for Neighborhood Electric Vehicles (NEVs). Model results are presented examining the utility of placing a hydrogen PEM fuel cell on-board a Miles Electric ZX40ST work truck NEV as an “after-market add-on” range extender to the existing battery electric drive train, ther...
Article
While conventional low-pressure LH2 dewars have existed for decades, advanced methods of cryogenic hydrogen storage have recently been developed. These advanced methods are cryo-compression and cryo-adsorption hydrogen storage, which operate best in the temperature range 30–100 K. We present a comparative analysis of both approaches for cryogenic h...
Article
A technical review of the progress achieved in hydrogen storage materials development through the U.S. Department of Energy’s (DOE) Fuel Cell Technologies Office and the three Hydrogen Storage Materials Centers of Excellence (CoEs), which ran from 2005 to 2010 is presented. The three CoEs were created to develop reversible metal hydrides, chemical...
Article
This report summarizes the 5-year R&D activities within the U.S. Department of Energy Metal Hydride Center of Excellence (MHCoE). The purpose of the MHCoE was to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials for light-duty vehicles. The MHCoE combined three broad areas: (a) mech...
Conference Paper
Fuel cells have been considered for all types of transport including automobiles, buses, submarines, motorcycles and airplanes due to their high efficiency and their environmentally friendly nature. In most transportation applications, fuel cells are used to augment the existing electrical system and not as a stand-alone power source. The addition...
Article
2LiNH2eMgH2 is considered an attractive material for reversible hydrogen storage. In an attempt to improve the hydrogen storage characteristics of the 2LiNH2eMgH2 system, the activation mechanism of the material, as well as the improvement in hydrogen absorption rates through doping were explored. Differential Scanning Calorimetry (DSC) investigati...
Article
Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole...
Article
Desorption and subsequent rehydrogenation of Mg(BH4)2 with and without 5 mol % TiF3 and ScCl3 have been investigated. Temperature programmed desorption (TPD) experiments revealed a significant increase in the rate of desorption as well as the weight percentage of hydrogen released with additives upon heating to 300 °C. Stable Mg(BxHy)n intermediate...
Article
A comprehensive model of radiation-induced carbon contamination of extreme ultraviolet (EUV) optics is presented. The mathematical model describes the key processes that contribute to the deposition of a carbon film on a multilayer optic when the optic is exposed to EUV radiation in the presence of residual hydrocarbons. These processes include the...
Article
A mathematical model of extreme ultraviolet (EUV)-induced oxidation of a ruthenium (Ru)-coated EUV optic is presented. The model describes the key processes that contribute to the growth of the oxide within the optic when exposed to EUV radiation in the presence of water vapor. These processes include the adsorption and thermal desorption of water...
Article
Full-text available
Experiments are presented that investigate the mechanistic cause of multilayer erosion observed from condenser optics exposed to EUV laser-produced plasma (LPP) sources. Using a Xe filament jet source excited with Nd-YAG laser radiation (300 mJ/pulse), measurements were made of material erosion from Au, Mo, Si and C using coated quartz microbalance...
Article
Method and apparatus for mitigating the transport of debris generated and dispersed from electric discharge sources by thermophoretic and electrostatic deposition. A member is positioned adjacent the front electrode of an electric discharge source and used to establish a temperature difference between it and the front electrode. By flowing a gas be...
Article
A “thermophoretic pellicle” has been proposed as an alternative to the traditional organic pellicle as a means of protecting extreme ultraviolet (EUV) lithographic photomasks from particle contamination. The thermophoretic pellicle protects a mask from particles by exploiting the thermophoretic force, which is exerted on a particle by a surrounding...
Article
Full-text available
Silicon capped [Mo/Si] multilayer mirrors (MLM"s) can undergo oxidation by the combined effects of radiation (Extreme Ultraviolet [EUV], electron) and water vapor. This parametric study provides silicon-capped MLM oxidation rate data. The goal of this study was to determine the dependence of silicon oxidation on water vapor pressure and radiation f...
Article
Full-text available
A critical issue in the realization of EUV lithography (EUVL) as a production technology is the lifetime of the condenser, the optic in closest proximity to any compact, high-power EUV source. During operation of the Engineering Test Stand (ETS), a full-field, high-power EUVL alpha tool, the silicon/molybdenum multilayer mirrors used as a condenser...
Article
A mathematical model is used to describe the processes that contribute to the deposition of a carbon film on EUV multilayer optics when the optic is exposed to EUV radiation in the presence of residual hydrocarbon gases. The key physical and chemical processes taken into account within the model include the transport of residual hydrocarbons to the...
Article
A technique is described that uses a gas-phase species to mitigate the oxidation of a Mo/Si multilayer optic caused by either extreme UV (EUV) or electron-induced dissociation of adsorbed water vapor. It is found that introduction of ethanol (EtOH) into a water-rich gas-phase environment inhibits oxidation of the outermost Si layer of the Mo/Si EUV...
Article
A high-resolution x-ray photoelectron spectroscopy (HRXPS) study of the Ni 3s core level is presented. Ni 3s HRXPS spectra were compared at T=298K (T=0.47Tc) and 863 K (T=1.37Tc). No significant variation with temperature is observed. These HRXPS results, combined with prior spin-resolved x-ray photoelectron spectroscopy studies of Ni core levels,...
Article
Recent studies have been conducted to investigate the use of atomic hydrogen as an in-situ contamination removal method for EUV optics. In these experiments, a commercial source was used to produce atomic hydrogen by thermal dissociation of molecular hydrogen using a hot filament. Samples for these experiments consisted of silicon wafers coated wit...
Article
Extreme ultraviolet (EUV)-induced oxidation of silicon-capped, [Mo/Si] multilayer mirrors in the presence of background levels of water vapor is recognized as one of the most serious threats to multilayer lifetime since oxidation of the top silicon layer is an irreversible process. The current work directly compares the oxidation on a silicon-cappe...
Article
The EUV Engineering Test Stand (ETS) is a full-field, alpha-class Extreme Ultraviolet Lithography (EUVL) tool that has demonstrated the printing of 70 nm resolution scanned images. The tool employs Mo/Si multilayer optics that reflect EUV radiation (13.4nm / 92.5eV) with ~67% peak reflectance per optic. For good reflectivity, many (>=40)Mo/Si layer...
Conference Paper
Extreme ultraviolet (EUV)-induced oxidation of silicon-capped, [Mo/Si] multilayer mirrors in the presence of background levels of water vapor is recognized as one of the most serious threats to multilayer lifetime since oxidation of the top silicon layer is an irreversible process. The current work directly compares the oxidation on a silicon-cappe...
Article
Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuu...
Article
An assessment was made of the extent of charging induced in a patterned multilayer-based extreme ultraviolet (EUV) mask and a model mask structure by exposure to EUV radiation. An aluminum subtractive metal lithography mask, consisting of ∼1700 Å of Al spaced from underlying Mo/Si multilayer by ∼500–700 Å of SiO2, was taken as representative of sub...
Article
Remote oxygen and hydrogen radio-frequency (rf) discharge cleaning experiments have been performed to explore their potential for cleaning carbon-contaminated extreme ultraviolet optics. The samples consisted of silicon wafers coated with 100 Å sputtered carbon, as well as bare Mo/Si multilayer mirrors (Si terminated). The samples were exposed for...
Article
A 'thermophoretic pellicle' has been proposed as an alternative to the traditional organic pellicle as a means of protecting EUV lithographic photomasks from particle contamination. The thermophoretic pellicle protects a mask from particles by exploiting the thermophoretic force, which is exerted on a particle by a surrounding gas in which a temper...
Article
The performance of Mo/Si multilayer mirrors (MLMs) used to reflect UV (EUV) radiation in an EUV + hydrocarbon (NC) vapor environment can be improved by optimizing the silicon capping layer thickness on the MLM in order to minimize the initial buildup of carbon on MLMs. Carbon buildup is undesirable since it can absorb EUV radiation and reduce MLM r...
Article
The EUV Engineering Test Stand (ETS) has demonstrated the printing of 100-nm-resolution scanned images. This milestone was first achieved while the ETS operated in an initial configuration using a low power laser and a developmental projection system, PO Box 1. The drive laser has ben upgraded to a single chain of the three-chain Nd:YAG laser devel...
Article
The EUV Engineering Test Stand (ETS) has demonstrated the printing of 100 nm resolution scanned images. This milestone was achieved with the ETS operating in an initial low-power configuration using a 40 W laser combined with a Xe cluster jet. The third condenser component is referred to as 'C3' illuminator optics was removed after this low-power o...
Article
Carbon contamination removal was investigated using remote RF-O2, RF-H2, and atomic hydrogen experiments. Samples consisted of silicon wafers coated with 100 Angstrom sputtered carbon, as well as bare Si-capped Mo/Si optics. Samples were exposed to atomic hydrogen or RF plasma discharges at 100 W, 200 W, and 300 W. Carbon removal rate, optic oxidat...
Article
A technique is described that uses radiation and a gas-phase species to produce a protective carbon coating on extreme ultraviolet (EUV) optics. A specific example is given in which a ∼5 Å carbon coating is deposited on EUV Mo/Si optics via coexposure to radiation (EUV photons, electrons) and ethanol vapor. Auger electron spectroscopy, sputter Auge...
Article
The EUV Engineering Test Stand (ETS) has demonstrated the printing of static and scanned 100 nm dense features. This milestone was first achieved in 2001 with a developmental set of projection optics (PO Box 1) and with a low power LPP source (40W drive laser). Since that time, the source has been upgraded to a 1500W (3 chains, 500W per chain) TRW...
Article
The Engineering Test Stand (ETS) is an EUV lithography tool designed to demonstrate full-field EUV imaging and provide data required to accelerate production-tool development. Early lithographic results and progress on continuing functional upgrades are presented and discussed. In the ETS a source of 13.4 nm radiation is provided by a laser plasma...
Article
The extreme ultraviolet (EUV) Engineering Test Stand (ETS) is a step-and-scan lithography tool that operates at a wavelength of 13.4 nm. It has been developed to demonstrate full-field EUV imaging and acquire system learning for equipment manufacturers to develop commercial tools. The initial integration of the tool is being carried out using a dev...
Article
The first environmental data from the Engineering Test Stand (ETS) has been collected. Excellent control of high-mass hydrocarbons has been observed. This control is a result of extensive outgas testing of components and materials, vacuum compatible design of the ETS, careful cleaning of parts and pre-baking of cables and sub assemblies where possi...
Article
Carbon deposition and removal experiments on Mo/Si multilayer mirror (MLM) samples were performed using extreme ultraviolet (EUV) light on Beamline 12.0.1.2 of the Advanced Light Source, Lawrence Berkeley National Laboratory (LBNL). Carbon (C) was deposited onto Mo/Si multilayer mirror (MLM) samples when hydrocarbon vapors where intentionally intro...
Article
Full-text available
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...
Article
The first environmental data from the Engineering Test Stand (ETS) has been collected. Excellent control of high-mass hydrocarbons has been observed. This control is a result of extensive outgas testing of components and materials, vacuum compatible design of the ETS, careful cleaning of parts and pre-baking of cables and sub assemblies where possi...
Article
An apparatus and method for in-situ cleaning of resist outgassing windows. The apparatus includes a chamber located in a structure, with the chamber having an outgassing window to be cleaned positioned in alignment with a slot in the chamber, whereby radiation energy passes through the window, the chamber, and the slot onto a resist-coated wafer mo...
Article
A removable pellicle for a lithographic mask that provides active and robust particle protection, and which utilizes a traditional pellicle and two deployments of thermophoretic protection to keep particles off the mask. The removable pellicle is removably attached via a retaining structure to the mask substrate by magnetic attraction with either c...
Article
A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source f...
Article
Full-text available
The Engineering Test Stand (ETS) is an EUV laboratory lithography tool. The purpose of the ETS is to demonstrate EUV full-field imaging and provide data required to support production-tool development. The ETS is configured to separate the imaging system and stages from the illumination system. Environmental conditions can be controlled independent...
Article
The Engineering Test Stand (ETS) is an EUV laboratory lithography tool. The purpose of the ETS is to demonstrate EUV full-field imaging and provide data required to support production-tool development. The ETS is configured to separate the imaging system and stages from the illumination system. Environmental conditions can be controlled independent...
Patent
A system that employs thermophoresis to protect lithographic surfaces from particle deposition and operates in an environment where the pressure is substantially constant and can be sub-atmospheric. The system (thermophoretic pellicle) comprises an enclosure that surrounds a lithographic component whose surface is being protected from particle depo...
Article
A technique for measurement of complex permittivity of dielectric materials, using coplanar waveguide (CPW) cells is presented. A complete solution of the forward and inverse problems, based on a quasi-TEM propagation model, is given. Unlike other methods, the inverse problem can be solved without the use of iterative or graphical techniques, by si...
Conference Paper
Extreme Ultraviolet Lithography (EUVL) is a candidate for future application by the semiconductor industry in the production of sub-100 nm feature sizes in integrated circuits. Using multilayer reflective coatings optimized at wavelengths ranging from 11 to 14 nm, EUVL represents a potential successor to currently existing optical lithography techn...
Article
Spin-resolved x-ray photoelectron spectroscopy (SRXPS) studies are reported of a high-binding-energy satellite associated with Fe 3s photoemission. The satellite is found to possess a complex spin polarization with three distinct components. Two majority-spin (↑-spin) components are observed with binding energies 111.0±0.5 and 123.4±0.5 eV. These m...
Article
Spin-resolved and high-energy-resolution x-ray-photoelectron spectra of the 3{ital d}, 4{ital d}, 4{ital f}, and 5{ital p} levels of ferromagnetic Gd are reported. The experimental spectra are compared with theoretical predictions for bulk Gd based on atomic multiplet calculations. The agreement is quite good when the Slater integrals are reduced t...
Article
Magnetic dichroism measurements using unpolarized MgKalpha radiation are reported for Fe 3s and 2s x-ray photoemission from ferromagnetic Fe. The Fe 3s level displays a small magnetic dichroism, whereas any dichroism present in the Fe 2s level is too small to be reliably detected. Since the Fe 3s level does not experience an initial-state spin-orbi...
Article
Recent spin‐resolved x‐ray photoelectron spectroscopy (SRXPS) studies of ferromagnetic metals are reviewed. SRXPS studies of metallic Fe, Co, Co 66 Fe 4 Ni 1 B 14 Si 15 , and Ni demonstrate that core‐level photoemission, and the itinerant electron response to core‐hole creation, are highly spin‐dependent. The exchange splitting of the Fe 2p 3/2 lev...
Article
Spin‐resolved x‐ray photoelectron spectroscopy and high‐resolution x‐ray photoelectron spectroscopy studies of the valence electronic structure of ferromagnetic Fe, Co, Co 66 Fe 4 Ni 1 B 14 Si 15 , and Ni are reported, and compared with theoretical densities of states. Agreement between theory and experiment is very good for ferromagnetic Fe and Co...
Article
We present an investigation of magnetic linear dichroism in angle-resolved photoemission distributions (MLDAD) from Fe(011) using unpolarized Mg Kα radiation. The experimental geometry is identical to that previously used in recent spin-resolved X-ray photoelectron spectroscopy (SRXPS) studies of ferromagnets. For this geometry, the results indicat...