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Mechanically reliable hybrid organosilicate glasses for advanced interconnects J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-05 Karsu Ipek Kilic; Reinhold H. Dauskardt
We explore the structure–property relationships in hybrid organosilicate glasses that form a special class of materials for use in advanced interconnects to improve their mechanical reliability by exploiting the structural characteristics most effectively. Our results show that hybrid organosilicate glasses that are hyperconnected and derived from organic linkers with optimal molecular geometry lead
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Selective lateral photoelectrochemical wet etching of InGaN nanorods J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-07 Chunyu Zhao; Xu Zhang; Chak Wah Tang; Jiannong Wang; Kei May Lau
Vertically aligned InGaN nanorods (NRs) sandwiched between GaN layers on sapphire substrates were synthesized by photoelectrochemical (PEC) wet etching. The InxGaN/InyGaN superlattice layer was laterally etched into NRs by selectively removing the material between dislocations due to the nonradiative recombination occurring at the dislocations. The mechanism of this PEC etching is examined in detail
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Atomic force microscopy for nanoscale mechanical property characterization J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-10 Gheorghe Stan; Sean W. King
Over the past several decades, atomic force microscopy (AFM) has advanced from a technique used primarily for surface topography imaging to one capable of characterizing a range of chemical, mechanical, electrical, and magnetic material properties with subnanometer resolution. In this review, we focus on AFM as a nanoscale mechanical property characterization tool and examine various AFM contact and
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Preparation of clean MgO surface by oxygen plasma: Comparison with standard substrate cleaning procedures J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-28 Jacqueline Geler-Kremer; Agham B. Posadas; Alexander A. Demkov
Different surface preparation methods for cleaning MgO, a widely used substrate in oxide epitaxy, are summarized and compared. We find that in situ surface preparation methods are preferable to ex situ preparation methods. We show that the complete removal of hydroxide, carbonate, and adventitious carbon from the MgO surface can be achieved via oxygen plasma exposure at 200 °C without high temperature
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Fabrication of free-standing silicon carbide on silicon microstructures via massive silicon sublimation J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-28 Mojtaba Amjadipour; Jennifer MacLeod; Nunzio Motta; Francesca Iacopi
Heteroepitaxial thin films of cubic silicon carbide (3C-SiC) on silicon offer a promising platform for leveraging the properties of SiC, such as wide bandgap, high mechanical strength, and chemical stability on a silicon substrate. Such heteroepitaxial films also attract considerable interest as pseudosubstrates for the growth of GaN as well as graphene on silicon wafers. However, due to a substantial
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Synthesis of TiN/N-doped TiO2composite films as visible light active photocatalyst J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-01 Glenson R. Panghulan; Magdaleno R. VasquezJr.; Yasmin D. Edañol; Narong Chanlek; Leon M. PayawanJr.
Titanium nitride/nitrogen-doped titanium oxide (TiN/N-doped TiO 2) composite films were synthesized for visible light photodegradation applications. Thin films of TiN were sputter-deposited on precleaned glass substrates in an admixture of argon and nitrogen gases. The grown TiN films were subsequently oxidized in air at 350 °C at 15, 30, and 60 min. Raman spectral analysis revealed the formation
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Investigation of the electrical behavior of AlGaN/GaN high electron mobility transistors grown with underlying GaN:Mg layer J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-05 Isra Mahaboob; Steven W. Novak; Emma Rocco; Kasey Hogan; Fatemeh Shahedipour-Sandvik
In the current study, the electrical behavior of the AlGaN/GaN high electron mobility transistors (HEMTs) grown with an underlying GaN:Mg layer is detailed. It is shown that the activation of the buried p-GaN layer is achieved without hydrogen diffusion out of the layer. Reversal in the electrical behavior of the two-dimensional electron gas (2DEG) is also observed in the as-grown structure based on
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Stability of TiO2-coated ZnO photocatalytic thin films for photodegradation of methylene blue J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-07 Rogel Jan B. Butalid; Anna Patricia S. Cristobal; Arantxa Danielle S. Montallana; Magdaleno R. VasquezJr.
Investigations on the stability of titanium dioxide ( TiO 2)-coated zinc oxide (ZnO) thin films upon repeated uses for methylene blue (MB) degradation were conducted. Photocorrosion of ZnO, upon exposure to light in aqueous media, can affect the photocatalytic performance due to loss of material. Hence, coating with a more stable metal oxide was seen as a way to suppress the effects of photocorrosion
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Au-free low-temperature ohmic contacts for AlGaN/AlN/GaN heterostructures J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-08 Xiaowei Wang; Hsien-Chih Huang; Bruce Green; Xiang Gao; Daniel Rosenmann; Xiuling Li; Junxia Shi
Au-free, Ti/Al/Ta ohmic contact on the AlGaN/AlN/GaN heterostructure using low annealing temperature is studied in this paper. With SiCl4 plasma treatment at the recess-etched contact region, a low contact resistance of 0.52 Ω mm and a low sheet resistance of 373 Ω/sq are achieved after annealing at 550 °C for 30 s. The low annealing temperature also leads to better surface morphology. Furthermore
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Postdeposition annealing effect on the reliability of atomic-layer-deposited Al2O3films on GaN J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-09 Kiyotaka Horikawa; Satoshi Okubo; Hiroshi Kawarada; Atsushi Hiraiwa
Atomic-layer-deposited (ALD) Al2O3 is a promising gate insulation material for wide-bandgap semiconductor devices of increasing importance for high-speed and high-power switching operation. This study comprehensively reports on postdeposition annealing (PDA) effects on the reliability of ALD-Al2O3/GaN metal-insulator-semiconductor capacitors. High-temperature (450 °C) ALD for the Al2O3 growth was effective
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Effect of oxygen vacancy gradient on ion-irradiated Ca-doped YMnO3thin films J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-09 Kunalsinh N. Rathod; Keval Gadani; Davit Dhruv; Vipul G. Shrimali; Sapana Solanki; Ashvini D. Joshi; Jitendra P. Singh; Keun H. Chae; Kandasami Asokan; Piyush S. Solanki; Nikesh A. Shah
In this study, we investigate the effect of ion irradiation on Y0.95Ca0.05MnO3 (YCMO) thin films. X-ray diffraction and Raman spectroscopy measurements show single-phase and strain/stress modifications with ion irradiation. Rutherford backscattering spectrometry confirms the variation in oxygen vacancies. The near-edge x-ray absorption fine structure shows valence state reduction of Mn ions, which
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Design of a remote plasma-enhanced chemical vapor deposition system for growth of tin containing group-IV alloys J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-09 Gordon Grzybowski; Morgan E. Ware; Arnold Kiefer; Bruce Claflin
Group-IV alloys of Ge and/or Si with Sn are challenging to prepare due to the low solubility of Sn in both of these elements. Herein, we describe a remote plasma-enhanced chemical vapor deposition (RPECVD) system designed to synthesize such group-IV alloys. Thin films of Ge, Ge1−ySiy, Ge1−xSnx, and Ge1−x−ySiySnx were deposited in the range of 280−410 °C on Si (001) substrates utilizing a remote He
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Superhydrophobic SnO2nanowire/graphene heterostructure-based ultraviolet detectors J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-12 Youngsoo Kang; Sanghyun Ju
As ultraviolet (UV) sensors are often employed in external environments, they should be able to function efficiently outdoors while remaining unaffected by liquids or changes in humidity. In this study, we developed a tin (IV) oxide nanowire (SnO2 NW)/graphene heterostructure-based UV detector that can accurately detect UV light without being affected by exposure to liquids. A (3,3,4,4,5,5,6,6,7,7
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Electrospun Mn2O3web electrodes: Influence of fabrication parameters on electrochemical performance J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-23 Molly Brockway; Jack L. Skinner
Supercapacitors are an important developing technology for renewable energy, hybrid and electric vehicles, and personal electronics. One material of interest for supercapacitor electrodes is Mn2O3, which is low cost, nontoxic, and easily fabricated. While traditional electrode fabrication involves mixing active materials with binders and conductive agents, electrospinning Mn2O3 fibers directly onto
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Effectiveness of multipass and multirow writing methods for massively parallel e-beam systems J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-02 Md Nabid Hasan; Soo-Young Lee; Byung-Sup Ahn; Jin Choi; Joon-Soo Park
Massively parallel electron-beam systems are equipped with a large number of beams to improve the writing throughput. It is unavoidable that some of the beams are abnormal, e.g., always on or off, spatial and temporal fluctuations of beam current, beam-positioning error, etc. A practical approach to improve the writing quality is to spread the negative effects of abnormal beams spatially. The multirow
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Cryogenic cleaning of tin-drop contamination on surfaces relevant for extreme ultraviolet light collection J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-07 Norbert Böwering; Christian Meier
Improvement of tool reliability and uptime is a current focus in the development of extreme ultraviolet lithography. The lifetime of collection mirrors for extreme ultraviolet light in tin-based plasma light sources is limited considerably by contamination with thick tin deposits that cannot be removed sufficiently fast by plasma etching. For tin droplet splats sticking to large substrates, we have
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Shape and dose control for proximity effect correction on massively parallel electron-beam systems J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-29 Md Nabid Hasan; Soo-Young Lee; Byung-Sup Ahn; Jin Choi; Joon-Soo Park
Massively parallel electron-beam (e-beam) systems (MPESs) were developed to increase the writing throughput and demonstrated to be able to write large-scale patterns significantly faster compared to conventional single-beam systems. However, such systems still suffer from the inherent proximity effect due to the electron scattering in the resist. The proximity effect correction (PEC) has been investigated
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Direct imprinting of TiO2patterns on highly curved substrates J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-30 Ming Luo; Xin Hu
In this paper, we demonstrate the fabrication of TiO2 patterns on both planar and various highly curved substrates via nanoimprint lithography followed by thermal treatment. First, a photocurable Ti-containing monomer is synthesized by reacting titanium (IV) ethoxide with 2-(methacryloyloxy)ethyl acetoacetate. The monomer is formulated with a visible light photoinitiator system to prepare a photocurable
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Bias-voltage-dependent measurement of apparent barrier height on low-work-function thin film J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-16 Katsumi Nagaoka; Shun-ichiro Ohmi
Using a scanning tunneling microscope, we have examined the effect of the bias voltage on the apparent barrier height. The sample used in this study was a nitrogen-doped lanthanum hexaboride film. We experimentally proved that a linear relationship exists between the apparent barrier height and the sample bias voltage. As a consequence, we estimated the work function of the film to be 2.35 eV by theoretical
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Effects of cavity shapes and rounded corners of mold on polymer filling process in nanoimprint lithography J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-23 Lijun Ma; Mingya Zhang; Xiaolei Zhang; Xu Zheng; Shifeng Xue; Qing Wang
The effects of cavity shapes and rounded corners on polymer filling and mold stress distributions of nanoimprint lithography are investigated using a numerical simulation approach. Three types of mold cavities including a rectangular cavity with vertical sidewalls, a trapezoidal cavity with inclined sidewalls, and a semicircular cavity with curved sidewalls are used to study the polymer flow and the
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Evidence of hydrogen termination at grain boundaries in ultrananocrystalline diamond/hydrogenated amorphous carbon composite thin films synthesized via coaxial arc plasma J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-02 Naofumi Nishikawa
Ultrananocrystalline diamond/hydrogenated amorphous carbon composite thin films consist of three different components: ultrananocrystalline diamond crystallites, hydrogenated amorphous carbon, and grain boundaries between them. Since grain boundaries contain many dangling bonds and unsaturated bonds, they would be a cause of carrier trap center degrading device performance in possible applications
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Comparative study on the molecular beam epitaxial growth and characterization of AlGaN nanowire structures on AlN buffer layer and on Si J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-11 Jiaying Lu; Yun Zhong; Songrui Zhao
AlGaN in the form of nanowires is an important platform for semiconductor ultraviolet light sources on Si. In the past, significant efforts have been devoted to improving the quality of AlGaN nanowires. In this context, we present a comparative study on the molecular beam epitaxial growth and characterization of AlGaN nanowire structures on the AlN buffer layer on Si and on Si directly. It is found
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Electrical characteristics, stability, electromigration, Joule heating, and reliability aspect of focused ion beam fabricated gold and copper nanobar interconnects on SiO2and glass substrates J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-20 Abhishek Kumar Singh; Jitendra Kumar
The electrical characteristics and stability of rectangular nanobar interconnects are investigated owing to their importance and reliability concern in electronic devices. One dimensional gold and copper nanobars (cross section 150–180 × 80–150 nm2 and length 3.0–5.0 μm), fabricated by milling of respective thin films with a 30 keV Ga+ ion probe (size 10–20 nm) at a current of ∼1 nA, are studied for
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Investigation of the current level instability of the multitip field emitters with computerized field emission projector J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-20 Anatoly G. Kolosko; Sergey V. Filippov; Eugeni O. Popov; Sergey A. Ponyaev; Alexandr V. Shchegolkov
This work represents a new approach for analyzing emission characteristics of multitip field cathodes. The approach is based on using a computerized field emission projector to investigate the behavior of the microscopic emission sites of the field cathode surface. Adsorption-desorption processes on the surface—which influence the emission current level—were investigated by tracking the individual
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Anomalous enhancement of focused ion beam etching by single raster propagating toward ion beam at glancing incidence J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-12-02 Joseph Favata; Valery Ray; Sina Shahbazmohamadi
Focused ion beam (FIB) sample preparation for electron microscopy often requires large volumes of materials to be removed. Prior efforts to increase the rate of bulk material removal were mainly focused on increasing the primary ion beam current. Enhanced yield of etching at glancing ion beam incidence is known but has not found widespread use in practical applications. In this study, etching at glancing
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Parylene micropillars coated with thermally grown SiO2 J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-15 Xiaocheng Liu; Peter Fecko; Zdenka Fohlerová; Tomáš Karásek; Jan Pekárek; Pavel Neužil
The modification of surface properties frequently requires the binding of suitable compounds to the original surface. Silanes or thiols can be directly covalently bonded to either Si-based materials or Au, thus ruling out polymers. Here, we show the utilization of a layer of SiO2 with a thickness of a few nanometers that serves as a cross-linker between polymers and silanes providing covalent bonding
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nanolithography toolbox—Simplifying the design complexity of microfluidic chips J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-10 Haoqing Zhang; Jan Pekárek; Jianguo Feng; Xiaocheng Liu; Huanan Li; Hanliang Zhu; Vojtěch Svatoš; Imrich Gablech; Pavel Podešva; Sheng Ni; Levent Yobas; Pavel Neužil
Microfluidic devices typically require complex shapes such as funnels, spirals, splitters, channels with different widths, or customized objects of arbitrary complexity with a smooth transition between these elements. Device layouts are generally designed by software developed for the design of integrated circuits or by general computer-aided design drawing tools. Both methods have their limitations
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Hybrid approach to modeling large area field emitters J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-28 Debabrata Biswas
Large area field electron emitters, typically consisting of several thousands of nanotips, pose a major challenge since numerical modeling requires enormous computational resources. We propose a hybrid approach where the local electrostatic field enhancement parameters of an individual emitter are determined numerically while electrostatic shielding and anode-proximity effects are incorporated using
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3D-electrode integrated microsieve structure as a rapid and cost-effective single neuron detector J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-06 Yagmur Demircan Yalcin; Regina Luttge
Using integrated silicon micromachining and thin-film technology, the fabrication of electrically functionalized microsieves for the study of 3D neuronal cell networks in vitro was a major challenge and is still very expensive at the current scale of device production, which is limited to fundamental research. Also, thin-film sidewall electrodes are in contact with the neurons and the microsieves need
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Sol-gel synthesized indium tin oxide as a transparent conducting oxide with solution-processed black phosphorus for its integration into solar-cells J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-09 Ravindra Mehta; Misook Min; Anupama B. Kaul
In this work, indium tin oxide (ITO) thin films were synthesized using solgel processing with a mixture of InCl3, methanol, and SnCl2, where the solutions were spin coated onto glass substrates. The maximum transmittance of the ITO thin film in the visible region was found to be ∼75% for films annealed at 650 °C, where plasma treatment of the substrate was found to aid in the large-area continuity
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Electromigration simulation and design considerations for integrated circuit power grids J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-20 Farid N. Najm; Valeriy Sukharev
Due to continued technology scaling, electromigration has become a serious reliability concern in modern integrated circuits. This is further aggravated by the pervasive use of inaccurate models for electromigration based on traditional empirical black-box models. We will review the modern approach to electromigration verification, with emphasis on recent physical models, then summarize our work on
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Advanced methodology for assessing chip package interaction effects on chip performance and reliability after chip assembly and during chip operation J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-30 Jun-Ho Choy; Valeriy Sukharev; Armen Kteyan
An advanced multiphysics EDA (Electronic Design Automation) methodology is presented for analyzing thermal and thermomechanical problems during chip assembly and operation. The tool-prototype, which was built on the basis of this methodology, employs an anisotropic effective thermal-mechanical property methodology that replaces building complex geometries in finite element analysis simulations, thereby
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Chip layout impact on stress-induced mobility degradation studied with indentation J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-12 Simon Schlipf; André Clausner; Jens Paul; Simone Capecchi; Laura Wambera; Karsten Meier; Ehrenfried Zschech
Chip-package interaction-caused mobility degradation in CMOS transistors is a critical degradation mechanism for microelectronic devices. An approach based on nondestructive indentation is applied to induce highly localized stress fields. Strain-sensitive ring oscillator circuits are integrated to monitor parametric deviations during mechanical loading. In this study, the indentation technique is used
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Mechanical analysis of a flexible microelectronic system under twisting stress J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-30 Cha-Hee Kim; Jae-Min Kim; Seung-Ho Seo; Jae-Hak Lee; Jun-Yeob Song; Won-Jun Lee
We modeled flexible microelectronic systems, in which a thinned silicon die is flip-chip bonded to a flexible substrate, and analyzed the stress and strain distribution generated during twisting deformation. Because of the presence of the rigid silicon die, the strain distribution of the system model was significantly different from that of the substrate model. Unlike the substrate model, there is
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Experimental reliability study of cumulative damage models on state-of-the-art semiconductor technologies for step-stress tests and mission profile stresses J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-28 A. Hirler; J. Biba; D. Lipp; H. Lochner; M. Siddabathula; S. Simon; T. Sulima; M. Wiatr; W. Hansch
Cumulative damage models are essential for reliability analysis, whether it is for the development of time-saving step-stress or ramp-stress life tests or for the qualification of products against mission-profile-based lifetime requirements. Although many cumulative damage models have been proposed in the literature, the discussion on them is rarely based on empirical data. In order to contribute to
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Energy distributions of secondary ions for the Ar ion beam sputtering of indium tin oxide J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-01 Carsten Bundesmann; Anke Hellmich
The energy distributions of secondary ions for the Ar ion beam sputtering of indium tin oxide were measured in dependence on geometric parameters (ion incidence angle, polar emission angle, scattering angle), ion energy, and O 2 background pressure using energy-selective mass spectrometry. The most prevalent ion species were identified to be O +, O 2 +, Ar +, In +, and Sn +. The energy distributions
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Phase errors reduction in multi-angle illumination digital holographic microscopy J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-10-05 Junsheng Lu; Yanan Zeng; Xinyu Chang; Yujian Hong; Xiaodong Hu
Synthetic aperture has been a common method in digital holographic microscopy resolution enhancement over the years. Multiangle illumination is one type of synthetic aperture methods. Reconstructed phase errors appeared when synthesizing aperture not considering the difference between different inclined incident beams' reconstruction distances. To reduce phase errors, this paper proposes a method using
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Investigations of internal stresses in high-voltage devices with deep trenches J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-11-11 Ellen Hieckmann; Uwe Mühle; Paul Chekhonin; Ehrenfried Zschech; Jeff Gambino
Deep trenches, as essential elements of silicon chips used in electronic high-power and high-frequency devices, are known as starting points for dislocation generation under the influence of internal mechanical stresses resulting mainly from the difference in the thermal expansion coefficients between silicon and silicon dioxide. Since the electrical insulation of the devices requires a sequence of
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Deterministic and stochastic modeling of rarefied gas flows in fusion particle exhaust systems J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-30 Christos Tantos; Stylianos Varoutis; Christian Day
In the present work, a deterministic approach is applied for the first time ever to simulate the rarefied gas flow in the particle exhaust system of a nuclear fusion device. As an example of such a system, the pumping area of the DEMO (DEMOnstration Fusion Power Plant) fusion reactor is considered, which is characterized by high geometrical complexity and strong gradients of macroscopic quantities
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Atomic spectroscopy and laser frequency stabilization with scalable micrometer and sub-micrometer vapor cells J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-26 Eliran Talker; Roy Zektzer; Yefim Barash; Noa Mazurski; Uriel Levy
We report on the atomic spectroscopy and laser frequency stabilization using a new type of a miniaturized glass vapor cell with a scalable thickness varying from 500 nm up to 8 μm. The cell is fabricated by lithography and etching techniques in a Pyrex glass substrate, followed by anodic bonding. It is filled with rubidium vapor using a distillation procedure. This simple and cost-effective fabrication
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Detecting nanoscale contamination in semiconductor fabrication using through-focus scanning optical microscopy J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-28 Min-Ho Rim; Emil Agocs; Ronald Dixson; Prem Kavuri; András E. Vladár; Ravi Kiran Attota
This paper reports high-throughput, light-based, through-focus scanning optical microscopy (TSOM) for detecting industrially relevant sub-50 nm tall nanoscale contaminants. Measurement parameter optimization to maximize the TSOM signal using optical simulations made it possible to detect the nanoscale contaminants. Atomic force and scanning electron microscopies were used as reference methods for comparison
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Dry etching strategy of spin-transfer-torque magnetic random access memory: A review J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-12 Rabiul Islam; Bo Cui; Guo-Xing Miao
The spin-based memory, spin transfer torque-magnetic random access memory (STT-MRAM), has the potential to enhance the power efficiency of high density memory systems. Its desirable characteristics include nonvolatility, fast operation, and long endurance. However, dry etching of MRAM structures remains a challenge as the industry is ramping up its production. In this paper, we explore the etching
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Folated curcumin-gold nanoformulations: A nanotherapeutic strategy for breast cancer therapy J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-18 Sneha Mahalunkar; Gopal C. Kundu; Suresh W. Gosavi
Breast cancer is considered a leading health problem, especially in women, and is a major contributor to the annual worldwide cancer mortality rate. Various drawbacks and a range of side effects are faced by cancer patients undergoing the conventional cancer therapy methods that do not always result in positive and successful outcomes. Current research introducing nanomaterials into in vivo breast
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Inks of dielectric h-BN and semiconducting WS2for capacitive structures with graphene J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-07-30 Jay A. Desai; Sangram Mazumder; Ridwan Fayaz Hossain; Anupama B. Kaul
We present dispersions of WS2 and h-BN using cyclohexanone and terpineol as the solvent to subsequently print prototype capacitive nanodevices. An all-inkjet-printing approach was used to print graphene-h-BN-graphene capacitors along with graphene-WS2-graphene structures. As the number of passes for inkjet printing the h-BN layer within graphene electrodes was increased, the leakage currents successively
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Effects of arsenic implantation and rapid thermal annealing on ZnO nanorods forp-type doping J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-07-31 Jinseok Choi; Sung Jin An
Ion implantation is a useful method of fabricating p-type zinc oxide (ZnO) nanorods; however, it typically causes structural defects in the substrate material. Rapid thermal annealing (RTA) is a well-known annealing process in the semiconductor industry used to restore lattice defects, and it has the advantage of a fast processing time. Herein, we report on the effects of arsenic (As) implantation
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Carbonization of 3D printed polymer structures for CMOS-compatible electrochemical sensors J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-04 Mohammad Aminul Haque; Nickolay V. Lavrik; Ava Hedayatipour; Dale Hensley; Dayrl P. Briggs; Nicole McFarlane
Carbon based electrodes suitable for integration with CMOS readout electronics are of great importance for a variety of emerging applications. In this study, we have looked into the prerequisites for the optimized pyrolytic conversion of 3D printed polymer microstructures and nanostructures with the goal of developing sensing electrodes for a lab-on-CMOS electrochemical system. As a result, we identified
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Anomalous minority carrier behavior induced by chemical surface passivation solution in p-type GaSb metal–oxide–semiconductor capacitors on Si substrates J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-05 Shun Sasaki; Katherine Dropiewski; Shailesh Madisetti; Vadim Tokranov; Michael Yakimov; Serge Oktyabrsky
p-type GaSb metal–oxide–semiconductor capacitors with thin InAs surface capping layers were prepared on Si(001) substrates. Epitaxial structures with superlattice metamorphic buffer layers were grown by molecular beam epitaxy. Chemical surface treatment and atomic layer deposition methods were employed for a semiconductor surface passivation and Al2O3 high-k oxide fabrication, respectively. Capacitance-voltage
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Electrical characterization of Si-doped conductive AlInN films grown nearly lattice-matched toc-plane GaN on sapphire by metalorganic chemical vapor deposition J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-11 Makoto Miyoshi; Taiki Nakabayashi; Mizuki Yamanaka; Takashi Egawa; Tetsuya Takeuchi
In this study, Si-doped conductive AlInN films with a thickness of 300 nm were grown nearly lattice-matched to c-plane GaN-on-sapphire templates by metalorganic chemical vapor deposition. A high net donor concentration of approximately 1 × 1019 cm−3 was observed for a highly Si-doped AlInN film. To evaluate its vertical-direction electrical resistivity without being affected by polarization-induced
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Real-time monitoring of photocatalytic methanol decomposition over Cu2O-loaded TiO2nanotube arrays in high vacuum J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-03 Hikaru Masegi; Hayato Goto; Shivaji B. Sadale; Kei Noda
We report a real-time investigation on the photocatalytic decomposition of methanol over Cu2O-loaded TiO2 nanotube arrays (TNAs) in high vacuum. Cu2O-loaded TNAs were fabricated using all-electrochemical processes. TNAs were prepared by anodizing Ti foils, and Cu2O nanoparticles (CNPs) were pulse-electrodeposited onto anodized TNA surfaces. The photocatalytic decomposition of methanol was monitored
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Study of a linear surface wave plasma source for tin removal in an extreme ultraviolet source J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-21 Dren Qerimi; Gianluca Panici; Arihant Jain; Daniel Jacobson; David N. Ruzic
Tin deposition mitigation employs hydrogen radicals and ions, formed in a hydrogen plasma, to interact with tin to form tin hydride ( Sn H 4) in the gaseous state, which is then pumped away. Surface wave plasma (SWP) technology developed at Illinois generates hydrogen radicals and ions, resulting in tin etch rates that are high enough to keep extreme ultraviolet (EUV) lithographic tools clean. An advantage
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Organotrialkoxysilane-mediated controlled synthesis of noble metal nanoparticles and their impact on selective fluorescence enhancement and quenching J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-07-27 Prem C. Pandey; Shubhangi Shukla; Govind Pandey; Roger J. Narayan
Ordered noble metal nanoparticles functionalized with organotrialkoxysilanes [e.g., 2-(3, 4-epoxycyclohexyl) ethyltrimethoxysilane (EETMS), 3-aminopropyltrimethoxysilane (APTMS), and 3-glycidoxypropyltrimethoxysilane (GPTMS)] were used as substrates to investigate the variation in fluorescence intensity of some well-known fluorophores (e.g., fluorescein, rhodamine, and l-tryptophan) based on distance
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Synthesis and up-conversion properties of Er3+doped ZnTiO3-Zn2TiO4composite phosphor J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-07-29 Sefako J. Mofokeng; Luyanda L. Noto; Kingsly O. Obodo; Odireleng M. Ntwaeaborwa; Robin E. Kroon; Mkhotjwa S. Dhlamini
The conventional solid state reaction method was used to prepare Er3+ activated ZnTiO3-Zn2TiO4 composite phosphor. The structure, particle morphology, absorption, and photoluminescent properties were analyzed using x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis-NIR absorption spectrometer, and photoluminescence (PL) spectroscopy, respectively. The XRD confirmed the crystallization
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Transport dynamics in a high-brightness magneto-optical-trap Li ion source J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-15 Jamie R. Gardner; William R. McGehee; Mark D. Stiles; Jabez J. McClelland
Laser-cooled gases offer an alternative to tip-based methods for generating high-brightness ion beams for focused ion beam applications. These sources produce ions by photoionization of ultracold neutral atoms, where the narrow velocity distribution associated with microkelvin-level temperatures results in a very low emittance, high-brightness ion beam. In a magneto-optical trap-based ion source, the
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Improvement of extra low impact energy SIMS data reduction algorithm for process control J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-07-31 Alexandre Merkulov; Paula Peres; Kilian Soulard; David John Larson; Karthik Sivaramakrishnan
This work explores quantitative boron depth profiling in the top first nanometer using dynamic secondary ion mass spectrometry (SIMS). Dynamic SIMS measurements were performed with a magnetic sector CAMECA IMS Wf/SC Ultra, using extremely low impact energy O2+ (below 250 eV) sputtering. It was concluded that the modification of quantification protocol by the creation of a surface transient curve can
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Surface preparation of porous Si-graphene nanocomposites for heteroepitaxy J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-22 Mourad Jellite; Maxime Darnon; Roxana Arvinte; Mohammad Reza Aziziyan; Denis Machon; Abderraouf Boucherif; Richard Arès
We have investigated the fabrication process of an alternative approach for a direct integration of epitaxial structures onto a foreign substrate. Our approach is based on the synthesis of a nanocomposite made of graphenelike carbon and porous silicon. The nanocomposite was produced by anodization etching of a silicon substrate followed by a thermal carbonization step. The main study focused on the
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Direct molecular quantification of electronic disorder inN,N′-Di-[(1-naphthyl)-N,N′-diphenyl]-1,1′-biphenyl)-4,4′-diamine on Au(111) J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-28 Jiuyang Wang; Jingying Wang; Daniel B. Dougherty
Organic light-emitting diodes are important in display applications, but thin films used in these devices often exhibit complex and highly disordered structures. We have studied the adsorption of a typical hole transport material used in such devices, N,N′-Di-[(1-naphthyl)-N,N′-diphenyl]-1,1′-biphenyl)-4,4′-diamine (α-NPD), on the Au(111) surface. Scanning tunneling microscopy images reveal the appearance
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Angular dependence of secondary electron yield from microporous gold surfaces J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-10 Jonathan Ludwick; Asif Iqbal; Daniel Gortat; John D. Cook; Marc Cahay; Peng Zhang; Tyson C. Back; Steven Fairchild; Martin Sparkes; William O’Neill
We report exhaustive measurements of the secondary electron yield (SEY) from a gold film containing an array of micropores as a function of the angle of incidence of the primary electrons. The SEY measurements are in good agreement with Monte-Carlo (MC) simulations. A highly accurate empirical fit to the SEY data as a function of the incident electron impact angle is also proposed. In this study, the
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Detection of some amino acids with modulation-doped and surface-nanoengineered GaAs Schottky P-I-N diodes J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-08-17 Tamador Alkhidir; Maguy Abi Jaoude; Deborah L. Gater; Christopher Alpha; A. F. Isakovic
Most current techniques for analyzing amino acids require substantial instrumentation and significant sample preprocessing. In this study, we designed, fabricated, and tested a scalable diode-based microdevice that allows for direct sensing of amino acids. The device is based on modulation-doped GaAs heterostructure with a Schottky contact on one side. The relatively high mobility and relatively small
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Ga-contamination-free scanning transmission electron microscope sample preparation by rectangular-shaped oxygen-ion-beam thinning using projection ion beam optical system J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-09 Hiroyasu Shichi; Satoshi Tomimatsu
Rectangular-shaped oxygen O2+ ion beam thinning for scanning transmission electron microscope (STEM) sample preparation was investigated using a projection ion beam optical system equipped with a duoplasmatron gas ion source. The ion current can be increased by increasing the area of the rectangular-shaped oxygen ion beam and thereby overcome the low brightness of the ion source. Rectangular-shaped
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Simple, low degree-of-freedom load-lock and in-vacuum sample transfer J. Vac. Sci. Technol. B (IF 1.511) Pub Date : 2020-09-11 Catlin N. Schalk; David A. Turner; Ashley R. Gans-Forrest; Matthew M. Jobbins; S. Alex Kandel
A mechanism is described for the loading and unloading of samples from an instrument housing in a way that achieves strong mechanical contact between the sample and housing. A single linear–rotary magnetically coupled feedthrough is required to effect transfer. An additional load-lock mechanism requires only a single linear magnetic feedthrough, which remains in the UHV part of the chamber. The load-lock