Sequential cyclic etching of copper thin films was performed using HBr/Ar gas and Ar plasma. The first step involved the formation of CuBrx layers by exposing copper thin films to HBr/Ar gas, and the second step involved the removal of the CuBrx layers by Ar ion sputtering. HBr/Ar gas was used to form the CuBrx layers, and the growth of CuBrx layers could be saturated under certain conditions. Ar ion

The inclusion of plasma in atomic layer deposition processes generally offers the benefit of substantially reduced growth temperatures and greater flexibility in tailoring the gas-phase chemistry to produce specific film characteristics. The benefits plasmas provide, however, come at the cost of a complex array of process variables that often challenge the ability to predict, a priori, the influence

Metal-insulator-metal tunnel junctions (MIMTJs) are an enabling technology for future electronics including advanced computing, data storage, sensors, etc. MIMTJs are formed by inserting an ultrathin insulating layer, known as the tunnel barrier (TB), between metal electrodes. Devices based on MIMTJs have advantages of enhanced quantum coherent transport, fast speed, small size, and energy efficiency

Throughout his career, Dr. Stephen Rossnagel and his co-workers have had a profound influence on thin film deposition. His seminal work includes the development of reactive, collimated, and ionized methods of DC and RF magnetron sputtering, as well as plasma-enhanced atomic layer deposition. Most importantly, his contributions have been widely adopted within the microelectronics community in its efforts

This review offers a succinct overview of the development of a vacuum-compatible microfluidic reactor system for analysis at the liquid vacuum interface (SALVI), and its diverse applications in in situ, in vivo, and in operando imaging of liquid surfaces as well as the air-liquid (a-l), liquid-liquid (l-l), and solid-liquid (s-l) interfaces in the past decade. SALVI is one of the first microfluidics-based

The understanding of fundamental processes in liquids and at the liquid/electrode interfaces of electrochemical systems is crucial for the development of new devices and technologies with higher efficiency and improved performance. However, it is generally difficult to isolate and study the component of interest in such complex systems. Additionally, ex situ analyses do not always reflect the same

We present a perspective on the use of XPS relative peak intensities for determining composition in homogeneous bulk materials. Nonhomogenous effects, such as composition variation with depth or severe topography effects (e.g., in nanoparticles), are not discussed. We consider only the use of conventional laboratory-based instruments with x-ray sources, Alkα or Mgkα. We address accuracy (not precision

X-ray photoelectron spectroscopy (XPS) is widely used to identify chemical species at a surface through the observation of peak positions and peak shapes. It is less widely recognized that intensities in XPS spectra can also be used to obtain information on the chemical composition of the surface of the sample and the depth distribution of chemical species. Transforming XPS data into meaningful information

Two-dimensional layered materials (2DLMs), MoS2 and WS2, and three-dimensional (3D) graphite were infused in thermoplastic polymer matrices comprised of acrylonitrile butadiene styrene (ABS) and polyethylene terephthalate glycol (PETG). Two processing approaches were examined for creating polymer tensile test specimens using the composites for mechanical testing, which included three-dimensional (3D)

The growth of vanadium dioxide (VO2) thin films using tetrakis (ethyl-methyl) amino vanadium (TEMAV) and H2O by atomic layer deposition (ALD) has been investigated as a function of the exposure dose and residence time. A novel multiple pulse mode has been employed to mitigate the small deposition rate brought about by the low vapor pressure of TEMAV. Compared to the conventional ALD cycle with a single

Some extremely reactive metals like Ce, U, and Pu are easily oxidized; instead of forming a stable surface oxide layer preventing further oxidation, the oxide layer break into powders as exposed to air in few days. For nuclear mineral industry, these materials need to be in storage for 1 month or so, which need to minimize surface oxidation. To provide a novel way to storage, atomic layer deposition

Cu2O and CuO are promising p-type semiconductor materials, which show potential for a variety of applications from photovoltaics to high-Tc superconductors. Atomic layer deposition (ALD) presents an advantageous technique for the growth of copper oxide due to the ability to grow on a variety of substrate materials and geometries with atomic precision in thickness and high uniformity. The work presented

The authors produce plasmonic ZnO-TiN nanocomposite films by depositing plasma-synthesized ZnO nanocrystals onto a substrate and then by infilling the nanocrystal network's pores with TiN via remote plasma-enhanced atomic layer deposition (PEALD). This ZnO-TiN nanocomposite exhibits a plasmonic resonance that is blueshifted compared to planar titanium nitride thin films. The authors study the effects

SiO2-Fe2O3 mixture films and nanolaminates were grown by atomic layer deposition from iron trichloride, hexakis(ethylamino)disilane, and ozone at 300 °C. Orthorhombic ɛ-Fe2O3 was identified in Fe2O3 reference films and in Fe2O3 layers grown to certain thicknesses between amorphous SiO2 layers. SiO2-Fe2O3 films could be magnetized in external fields, exhibiting saturation and hysteresis in nonlinear

Area-selective bottom-up synthesis routes of thin films are required to overcome the current limits in lithography, and such growth can be achieved with high quality and nanometer thickness control by area-selective atomic layer deposition (AS-ALD). However, the current range of materials demonstrated deposited by AS-ALD is limited, and no processes for molybdenum oxide have been available so far.

Thin hafnium oxide films were prepared by atomic layer deposition using a carbon-free precursor, tetrakis(tetrahydroborato)hafnium [Hf(BH4)4], and H2O. Film growth was studied using an in situ quartz crystal microbalance and Fourier transform infrared spectroscopy measurements. Self-limiting growth was observed between 100 and 175 °C, but the thermal decomposition of the Hf precursor occurred at higher

This paper investigates manganese-doped zinc oxide (ZnMnO) thin films grown using the atomic layer deposition (ALD) technique. ZnO and MnO layers were deposited alternatively using diethyl zinc and manganese (III) acetylacetonate (Mn(acac)3) as metallic precursors. A suppressed growth rate for both materials was observed during the growth of ZnMnO samples, which is due to reduced adsorption of the

In this work, the authors have investigated the dependence of the anisotropy level in an atomic layer etching (ALE) process of Al2O3 on form factor constraints when the ALE process involves etching in non-line-of-sight locations beneath a silicon nitride mask. In the experiments described here, thermal etching of Al2O3 without the use of any direction-inducing plasma components was explored utilizing

Gallium nitride (GaN) semiconductor devices must be fabricated using plasma etching with precise control of the etching depths and minimal plasma-induced damage on the atomic scale. A cyclic process comprising etchant adsorption and product removal may be suitable for this purpose but an understanding of the associated etching surface reactions is required. The present work examined the formation of

The stringent requirement for patterning highly absorbing metal thin films as a mask for the next-generation extreme ultra-violet lithography system dictates the development of an atomic layer etching process to tailor the etch rate and the etch profile. A “plasma-thermal” atomic layer etching process is developed where an oxygen plasma is used to convert the metallic Ni layer into NiO, followed by

A two-step plasma-thermal atomic layer etching (ALE) process that is capable of etching Ni with high selectivity with respect to the SiO2 hard mask and high anisotropy is evaluated in this work with a reactive ion etching (RIE) process to highlight the contrast between these two processes and the advantages of combining these two processes to tailor the sidewall profile with greater processing efficiency

This work examines the effect of the frequency and peak applied voltage on hydroxyl-radical generation in a dielectric-barrier plasma discharge between a metallic needle electrode and one electrode covered with dielectric. The authors examine a system that can expose up to 96 liquid samples in an automated fashion without human intervention beyond setting the initial software configuration. Then, hydroxyl-radical

Vacuum ultraviolet-absorption spectroscopy (AS) and emission spectroscopy (ES) from delocalized probe plasma are implemented in the downstream chamber of a soft-etch industrial plasma reactor. A capacitively coupled plasma plasma, running in the upper compartment in He/NF3/NH3/H2 mixtures at about 1 Torr, produces reactive species which flow through a shower head into a downstream chamber, where they

Yttrium oxyfluoride was developed for use in the plasma process chamber using various corrosive gases. In this paper, sintered yttrium oxyfluorides with various Y, O, and F composition ratios (YxOyFz) and ion-plated YOF and Y5O4F7 films were prepared, and the physical etching behavior due to Ar ion bombardment and NF3/Ar plasma resistance was investigated. It was found that the etching rate of the

Black silicon (BSi or silicon micro/nanograss) is a frequently encountered phenomenon in highly directional etching of silicon using mainstream plasma etch tools. The appearance of BSi in most studies is considered to be caused by micromasks unintentionally present on the silicon surface that locally prevent silicon from etching. Particularly, under highly directional and selective plasma etch conditions

In this work, a special focus is given to atomic layer etching (ALE) of metals, since this is a relatively new field but is expected to grow rapidly given the major advancements potentially enabled via metal incorporation throughout the manufacturing process of integrated circuits. The impact of John Coburn’s work on the development of ALE processes is analyzed with a focus on ion energy and the neutral-to-ion

The authors explore the combination of high power impulse magnetron sputtering (HiPIMS) and substrate bias for the epitaxial growth of the Cu film on the Cu (111) substrate by molecular dynamics simulation. A fully ionized deposition flux was used to represent the high ionization fraction in the HiPIMS process. To mimic different substrate bias, the authors assumed the deposition flux with a flat energy

Atomic layer etching (ALE) techniques are growing in popularity due to their various benefits such as low damage, high selectivity, and precise and controlled etching. In ALE, surface modification is typically achieved by chemisorption of radicals generated in a plasma followed by ion assisted removal of the modified surface. A surface modification process assisted by a plasma may lead to unwanted

The adsorption of organic molecules on surfaces has played an important role in the development of key technologies available today. These molecules provide unique functionalities and properties to the surface that will not exist otherwise. This article will focus on identifying the role of small organic molecules in applications related to energy, sensing, and electronics. Specifically, the authors

Developing low temperature, low cost metal oxide gas sensors remains a critical but elusive goal. Additionally, a better understanding of gas-metal oxide interactions during sensing is required to achieve this goal as well as improving the performance of these devices. Here, the authors describe a paper-based gas sensor (PGS) utilizing SnO2 nanoparticles to detect ethanol, CO, and benzene. Proof-of-concept

In this study, vapor phase deposition of quaternary ammonium polymers on different substrates was reported. Thin films of the poly(diethylaminoethyl methacrylate) (PDEAEMA) homopolymer and the poly(diethyl aminoethyl methacrylate-co-vinylbenzyl chloride) [P(DEAEMA-VBC)] copolymer were deposited by an initiated chemical vapor deposition (iCVD) technique using tert-butyl peroxide as an initiator. The

During the last few years and with the commercialization of the gallium nitride based high electron mobility transistor, research effort on gallium nitride has been strongly increasing. Besides activities regarding lateral devices like the gallium nitride high electron mobility transistor, progress in the growth of native gallium nitride substrates encourages the development of vertical devices. In

The development of materials for industrial applications is in constant evolution. Regarding environmental or health laws, the use of some materials is restricted (lead-based). In this context, lithium niobate (LiNbO3) is studied in order to develop the performances of the RF (radio frequency) applications (for instance, filters using the bulk acoustic wave or surface acoustic wave technology). The

The performance and calibration of an XPS instrument can change with time. Changes may be gradual so that users may not notice them from day to day unless they actively compare the current performance of the instrument with its recently optimized performance. This publication describes a method by which such a comparison may be made very rapidly. A tool, based on a Microsoft Excel workbook, has been

Here, the authors present a novel solid-state nanopore device, fabricated by a transfer of a nanopore device to a dielectric polydimethylsiloxane (PDMS) microchannel-guided structure, and investigate the characteristics of DNA translocation through the nanopore. Apart from the extremely low noise level exhibited by this device on a highly insulating and low dielectric PDMS microchannel, this device

Thin films of the sp2-hybridized polytypes of boron nitride (BN) are interesting materials for several electronic applications such as UV devices. Deposition of epitaxial sp2-BN films has been demonstrated on several technologically important semiconductor substrates such as SiC and Al2O3 and where controlled thin film growth on Si would be beneficial for integration of sp2-BN in many electronic device

The authors investigate unintentional Si doping in β-Ga2O3 thin films grown via plasma-assisted molecular beam epitaxy. By identifying the Si dopant cell and the radio frequency oxygen plasma source as the two major sources of unintentional Si present in the growth chamber, adjustments to the parameters controlling these sources allow for the reduction of unintentional Si doping in β-Ga2O3 films by

The self-cleaning properties emerging from photocatalytic effects consist in the elimination of an organic contamination layer by light-induced redox reactions. Quartz crystal microbalances (QCMs), monitoring the contaminant mass loss under UV illumination, were used to investigate this effect and its efficiency. A new setup dedicated to such purpose is introduced along with the results of a self-cleaning

Achieving high carrier mobilities and low carrier densities has been one of the major challenges in the growth of BaSnO3 thin films. In this study, unintentional carbon impurities are investigated as one possible cause for poor electrical transport. Carbon concentrations in La-doped BaSnO3 films grown by molecular beam epitaxy using solid SnO2 sources are quantified using secondary ion mass spectroscopy

The authors study the morphological evolution of magnetron-sputtered thin silver (Ag) films that are deposited on weakly interacting silicon dioxide (SiO2) substrates in an oxygen-containing (O2) gas atmosphere. In situ and real-time monitoring of electrically conductive layers, along with ex situ microstructural analyses, shows that the presence of O2, throughout all film-formation stages, leads to

Gallium oxide (Ga2O3) thin films were laser ablation deposited on Si(100) substrates in vacuum, argon, and oxygen (O2) at different substrate temperatures by using the pulsed laser deposition technique. X-ray diffraction patterns showed that the films were crystallized in a mixed phase of β-Ga2O3 and Ga(OH)3. Data from scanning electron microscopy and atomic force microscopy showed that the major influence

High power impulse magnetron sputtering (HiPIMS) of diamond-like carbon coatings is reviewed. Three variations of HiPIMS were used to deposit diamond-like carbon coatings: use of neon as compared to argon for sputtering, very high discharge peak current density in an Ar atmosphere, and the use of bursts of short sputtering pulses. All three variations were able to provide sufficient ion-to-neutral

Accurate electron attenuation lengths are of critical importance in using electron spectroscopic methods to quantitatively characterize complex materials. Here, the authors show that analysis of core-level and valence-band x-ray photoelectron spectra excited with monochromatic AlKα x-rays from the substrate and measured as a function of film thickness can be used to determine electron attenuation lengths

A 50 × 50 mm 2 copper target is sputtered by an ion beam at angles of incidence from 0 ° to 90 °. The resulting sputter plumes are characterized directionally resolved using a compact and maneuverable force probe. It measures the momentum flux of particles released due to sputtering or reflection inside the sputter plume. Argon ions at energies from 320 to 1220 eV are studied. As expected, the directional

Atmospheric pressure plasma jets have great potential for the surface modification of polymers. In this work, the authors report on polystyrene etching by a radio frequency driven atmospheric pressure plasma jet with a focus on the role of H ⋅, O ⋅, and ⋅ OH radicals in this process. The absolute flux of H ⋅, O ⋅, and ⋅ OH radicals reaching the surface of the polymer was determined by a comsol multiphysics

While the basal plane of single-layer molybdenum disulphide (MoS2) is inert, attempts have been made to functionalize it chemically through the creation of defects and/or addition of dopants. With nanoparticles as dopants, the authors present density functional theory-based calculations of the hydrogenation of CO on a 31-atom, bilayer Au cluster supported on single-layer MoS2 (Au31/MoS2). Not surprisingly

Two-dimensional transition metal dichalcogenides (2D TMDs) is one of the promising materials for future electronics since they have, not only superior characteristics, but also a versatility that conventional materials do not have with a few nanometer thickness. One of the prerequisites for applying these materials to device fabrication is to deposit an ultrathin film below 10 nm with excellent uniformity

Layered cobalt oxides based on the hexagonal CoO2 layer, e.g., NaxCoO2 and [CoCa3O3]0.62CoO2 (or “Ca3Co4O9”), are promising thermoelectric materials. Here, the authors investigate the atomic layer deposition (ALD) of these materials in a thin-film form; this is not trivial, in particular, for the former compound, as both Na and Co are little challenged as components of ALD thin films. The authors employ

The authors report novel results toward optimizing the electrochemical performance of high vacuum deposited lithium-based all solid-state thin film microbatteries. This study investigated hermetic encapsulation, interfacial lithium formation processes, and the role of Li-blocking and Li-nucleating layers for improved Li-metal plating on copper anodes. Photoresist was found to be an effective temporary

This guide deals with methods to control surface charging during XPS analysis of insulating samples and approaches to extracting useful binding energy information. The guide summarizes the causes of surface charging, how to recognize when it occurs, approaches to minimize charge buildup, and methods used to adjust or correct XPS photoelectron binding energies when charge control systems are used. There

The properties of secondary particles for sputtering silicon with primary low-energy oxygen ions were investigated with dependence on the primary ion energy Eion and geometric parameters (ion incidence angle, polar emission angle, and scattering angle). The mass and energy distributions of the secondary particles were measured by energy-selective mass spectrometry. The experimental results were compared

Determination of molecular temperatures within low-temperature plasmas is critical to understanding the reactions that drive the chemistry of these systems and the mechanisms involved in plasma-surface interactions. Optical emission spectroscopy was employed to investigate gas-phase processes in H2 and CH4 inductively coupled plasma systems. Specifically, rotational temperatures (TR) have been determined

The use of inconsistent and incorrect terminology in scientific publications contributes to misunderstanding, confusion, and erroneous results in the scientific literature. This issue is of particular importance in x-ray photoelectron spectroscopy (XPS) that is in widespread use for many different purposes by scientists with diverse backgrounds. A set of surface analysis terminology, approved through

An essential element to realize lithium-ion microbatteries is an effective and conformal thin film solid state electrolyte over irregular or porous structures with specific composition and controlled elemental spatial distribution. Atomic layer deposition is a surface reaction based and non-line-of-sight technique that can rationally design an optimal electrolyte material, including high conductivity

In this paper, the emerging role of ionic species in plasma assisted chemical deposition processes is discussed in detail for commemorating the Career of John Coburn, who studied the role of ionic species in plasma etching processes forty years ago. It is shown that, in both plasma enhanced chemical vapor deposition and plasma enhanced atomic layer deposition processes, plasma ions can play a major

In high power impulse magnetron sputtering (HiPIMS) operation, there are basically two goals: a high ionized flux fraction of the sputtered target material and a high deposition rate. In this work, it is demonstrated that the former always comes at the cost of the latter. This makes a choice necessary, referred to as the HiPIMS compromise. It is here proposed that this compromise is most easily made

The sideways (radial) deposition rate and ionized flux fraction in a high power impulse magnetron sputtering (HiPIMS) discharge are studied and compared to a dc magnetron sputtering (dcMS) discharge, while the magnetic field strength | B | and degree of balancing are varied. A significant deposition of the film forming material perpendicular to the target surface is observed for both sputter techniques

Nanolaminated aluminum oxide (Al2O3)/hafnium oxide (HfO2) thin films as well as single Al2O3 and HfO2 layers have been grown as gate dielectrics by the plasma enhanced atomic layer deposition technique on silicon carbide (4H-SiC) substrates. All the three dielectric films have been deposited at a temperature as low as 250 °C, with a total thickness of about 30 nm, and, in particular, the nanolaminated

Through-silicon vias (TSVs) are a critical technology for three-dimensional integrated circuit technology. These through-substrate interconnects allow electronic devices to be stacked vertically for a broad range of applications and performance improvements such as increased bandwidth, reduced signal delay, improved power management, and smaller form-factors. There are many interdependent processing

In the gate-recess formation process, normally-off operation is achieved by removing the barrier layer by dry etching to reduce the two-dimensional-electron-gas concentration under the gate electrode. An atomic-layer defect-free etching of GaN is thus indispensable to achieve high-frequency, high-power, and normally-off operation. More-precise atomic-layer defect-free GaN etching was investigated by