Silicon field emitter arrays (FEAs) with different tip sizes and quantities were fabricated by saw dicing and anisotropic wet chemical etching by tetramethylammonium hydroxide. The tip is formed by the different etching rates of the crystal facets leading to a sharp pyramid based on {103} planes on the top and a hexadecagon based on {331} and {221} planes on the bottom. Electrical measurements at 10−5 mbar

The scanning tunneling microscope (STM) has enabled manipulation and interrogation of surfaces with atomic-scale resolution. Electronic information about a surface is obtained by combining the imaging capability of the STM with scanning tunneling spectroscopy, i.e., measurement of current-voltage (I/V) characteristics of the surface. We propose a change in the STM feedback loop that enables capturing

A variety of nonvolatile memory (NVM) devices including the resistive Random Access Memory (RRAM) are currently being investigated for implementing energy-efficient hardware for deep learning and artificial intelligence at the edge. RRAM devices are employed in the form of dense crosspoint or crossbar arrays. In order to exploit the high-density and low-power operation of these devices, circuit designers

Electromigration—a critical failure mode of metal interconnects in integrated circuits—has been exploited for constructing nanometer-sized gaps (or nanogaps, less than a few nanometers) on metallic nanowires. Electromigrated nanogaps have been utilized extensively in the field of nanotechnology and have demonstrated to be an effective platform for electrically accessing small things such as molecules

Ionic liquid/ionogel gate dielectrics can provide significant advantages for transistor architectures that utilize high surface area semiconductors and/or nonplanar substrates because of their cleanroom-free, liquid-based processability and their inherently large electrostatic double layer capacitance. These attributes of ionogels have already enabled the facile fabrication of several up-and-coming

Planar metal-insulator-semiconductor capacitors are fabricated on native gallium nitride substrates with different gate dielectrics, namely, silicon dioxide, silicon nitride, and aluminum oxide. The leakage current was measured to determine their robustness regarding electrical breakdown. Hysteresis effects were evaluated for the different gate dielectrics and for the substrate and the epitaxial surface

ZnO thin film transistor with high-k NbLaO/SiO2 bilayer gate dielectric was fabricated by sputtering, and the temperature dependence of the electrical properties of the device was investigated in the temperature range of 293–353 K for clarifying thermally activated carrier generation and carrier transport mechanisms in the conducting channel. With the increase in the temperature, the transfer curve

Reported is the manufacture and optimization of inverted micropyramid cavity structures into thermoplastic sheets using roll-to-roll (R2R) embossing. To manufacture the master, an ultraprecision diamond machining method was applied to create seamless surface structures into a copper-coated hot embossing roller. Using the hot embossing process, the roller features were successfully transferred to 2 mm

The design, fabrication, and characterization of single metal gate layer, metal-oxide-semiconductor (MOS) quantum dot devices robust against dielectric breakdown are presented as prototypes for future diagnostic qubits. These devices were developed as a preliminary solution to a longer term goal of a qubit platform for intercomparison between materials or for in-line diagnostics and to provide a testbed

Crystalline thin films of Eu, Dy, and Er-doped CaWO4 and CaMoO4 of thicknesses 100–150 nm were synthesized by pulsed laser deposition on fused silica substrates. The atomic force and scanning electron microscopy studies confirm uniform and dense surface morphology of the samples. Tetragonal CaWO4 films show preferred growth of crystallites of (112) orientation. CaMoO4 shows texturing of crystallites

We report observation of the piezoresistive effect of β-Ga2O3 Schottky diodes and investigate its application for strain gauge sensors. The Schottky diode-based strain gauge exhibits resistance on the order of 107 Ω, which allows low power applications. A large gauge factor of −201 ± 43 is measured from a Pt/( 2 ¯01) β-Ga2O3 Schottky diode at room temperature, enabling the strain-induced resistance

Simulation has been performed on fully lead-free inorganic cesium germanium tri-iodide (CsGeI3) perovskite solar cell heterostructure and achieved a champion power conversion efficiency (PCE) of ∼18.30% with significantly improved device parameters. The influence of thickness of an electron transport layer, a hole transport layer, an absorber, defect density, doping concentration, electron affinity

This study aimed to reveal the electrical characteristics of the composite electrodes of Li-ion batteries. LiCoO2 electrodes were analyzed using atomic force microscopy, and three-dimensional datasets of current–voltage (I–V) curves (IV-datacubes) were obtained. The IV-datacubes were then analyzed using principal component analysis to determine the typical I–V curve corresponding to each LiCoO2 particle

Optimizing the locations and sizes of droplets is the key to reducing defects and increasing throughput of ultraviolet nanoimprint lithography. In practice the templates are composed of regions with different structures. The interface between structures will generate complicated fluid flow behavior that will slow the filling time. Here, we explore several strategies through simulations to distribute

The high suitability of hydrogen silsesquioxane (HSQ) as e-beam resist has long been known. Despite its undoubtedly good and reliable properties, HSQ nevertheless proves to be problematic in certain aspects due to its relatively short shelf-life and the small processing window between coating preparation and exposure. We thus intended to optimize the silsesquioxane with respect to a prolonged shelf-life

Computational lithography is typically based on a model representing the lithographic process where a typical model consists of three components, i.e., line spread function, conversion formula (exposure-to-developing rate conversion), and noise process (exposure fluctuation). In our previous study, a practical approach to modeling the e-beam lithographic process by deriving the three components directly

Nanofabrication is a remarkably effective technique to create desirable nanoscale patterns. In this work, the effect of surface nanofabrication on altering virus adhesion to the substrates was examined. Arrays of nanoholes, 50 nm in diameter, 22 nm deep, and 100 nm in pitch distance, were created on silicon (Si) wafers by electron-beam lithography and reactive ion etching. MS2 coliphage, which is 26 ± 2 nm

We present a new Li source for focused ion beam applications. Based on an AuSi eutectic alloy, Li is added as an impurity to minimize effects from degradation when exposed to air. We show the source is stable over the course of an hour and spot sizes ≲ 10 nm can be achieved. The Li beam can achieve hundreds of nanometer ranges in semiconductors with minimal damage being generated along the path length

Our study refers to the highly stretchable elastomer PDMS (polydimethylsiloxane), a material used with a wide range of applications. Its basic mechanical properties can be tuned, e.g., by varying the curing conditions; moreover, its surface properties can be tuned by modification techniques. We modified our PDMS by irradiating the samples with an excimer lamp at 172 nm. Such a treatment hardens the

In this work, self-heating effects (SHE) in nanometer-scale metal-oxide-semiconductor field-effect transistor structures—namely, FinFETs (FFs), nanosheet gate-all-around FETs (NSFs), and nanowire gate-all-around FETs (GAAFs)—are investigated via three-dimensional device electrothermal simulations using technology computer-aided design software tools. Initially, transistor design parameter values are

A cerium hexaboride (CeB6) single crystal grown by the floating-zone method has a low work function of about 2.6 eV, and along with lanthanum hexaboride (LaB6), it is one of the most popular cathode materials. It has been widely used as the thermionic emitter of electron microscopes, such as SEMs and TEMs. However, cold-field emitters (CFEs) based on CeB6 and LaB6 have not been put to practical use

A recently developed novel methodology for electromigration (EM) failure assessment in power/ground grids of integrated circuits is employed in the electronic design automation tool prototype. The tool performs the analysis of stress evolution in interconnect trees for detecting EM-induced voiding locations and tracks resistance increase in the voided wires based on a physics-based model of voiding

We report the results of the design, simulation, fabrication, and cold-test measurements of millimeter-band 2D planar microstrip slow-wave structures (SWSs) on dielectric substrates. Such structures have a high slow-wave factor, which allows for low-voltage operation and reduction in the size and weight of the device. A low-cost and flexible fabrication technology based on magnetron sputtering and

Molecular beam epitaxial (MBE) deposition allows for the epitaxial growth of materials requiring atomically precise control of nanometer thick layers. A key concern with the growth of smaller bandgap materials on larger bandgap substrates via MBE is the radiative coupling of the deposited layer with the heater, which can lead to uncontrolled increases in temperature if not properly accommodated for

We observed the polarity-dependent thermionic emission (TE) and conversion characteristics of n-type GaN-based cathodes with Cs adsorbed on their surfaces. TE current from the surface of an n-GaN sample with N-polarity was 0.18 mA at an applied anode voltage of 30 V at 500 °C. This TE current was markedly higher than that of a sample with Ga-polarity, which had a corresponding TE current of 0.063 mA

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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