bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrodeposition of Zn - Ni Alloys from Protic Ionic Liquids
Authors: Ortega Borges Raul Martin , Garcia Ramos Tania , Trejo Córdova Gabriel , Meas Vong Yunny 
Published: February 2020

Electrodeposition of metals and alloys is currently carried out from aqueous solutions despite the environmental problems associated to the complex baths needed to obtain electrodeposits with controlled properties (composition, roughness, etc). In this context, ionic Liquids (IL) are studied as an option to be used as new green solvents for electrodepositon due to their interesting properties : non volatility, low fusion temperature, conductivity, viscosity, etc. However, commercial LIs are generally toxic and highly reactive in the presence of water which limits their application in many chemical and electrochemical processes. In this work, we study the use of environmentally friendly and stable protic ionic liquids (PILs) as solvents in the electrochemical deposition of nanostructured metals (Ni and Zn) and their alloys.
The studied PILs synthetized by using well-known amounts of a linear aliphatic amine and a single-chain carboxylic acid as precursors in order to get mixtures of controlled composition (e.g., pure PIL or mixture of a pure PIL and its pure acidic or basic precursor as a co-solvent) to be applied directly as the depositon bath in the electrochemical deposition of nanostructured nickel, zinc and their alloys.
The electrodeposition process was studied by electrochemical techniques and the obtained deposits were characterized by optical microscopy and also by SEM and AFM techniques. For the electrodeposition of the studied single metals (Ni and Zn), results shown that nanostructured nickel and zinc deposits can be electrodeposited from these protic ILs with faradic efficiencies dependent on the composition of the IL and on the temperature; the influence of the physicochemical properties of the studied PILs and of the temperature on the morphological characteristics of the obtained deposits were also evaluated. The major effects were attributed to the influence of composition on mass and charge transfer properties of the PILs.
In the case of the electrodeposited Ni-Zn alloys, results allow to evaluate the influence of the composition of the ionic liquid on the composition of the electrodeposited alloys. In these media, it is observed that Zn-rich alloys are commonly formed. The morphology of the obtained electrodeposits are strongly dependent on the temperature.
These results allow conclude that the studied PILs are good as new reaction media with tunable properties for electrochemical applications, allowing to propose them as new systems for electrodeposition processes, as new single solvents without the use of organic additives.
Acknowledgements: Authors gratefully acknowledge financial support from SEP–CONACyT Program (Project CB 2011-1-168032). TBGR is indebted to CONACYT for the fellowship.
Ion Intercalation into 2D Titanium Carbide Based MXenes: Applications for Electrochemical Capacitors
Authors: Lukatskaya Maria R. , Ren Chang E. , Mashtalir Olha , Dall'Agnese Yohan , Barsoum Michel W. , Simon Patrice , Gogotsi Yury 
Published: February 2020

We recently produced a new 2-D material, viz. Ti3C2, by selectively etching aluminium from a MAX phase Ti3AlC2 and labelled it MXene. MXenes represents a large family of transition metal carbides and carbonitrides, not just a single phase. Unlike graphene, whose chemistry is restricted to carbon, MXenes allow a variety of chemical compositions and are establishing themselves as a new class of two-dimensional materials. MXenes possess good in-plane conductivity, which in combination with the rich surface chemistry makes them attractive for electrical energy storage applications. However while potential of MXenes as anode materials for Li-ion batteries has already been shown, their use in electrochemical capacitors has not been explored.
Herein, we report on the intercalation of Li+, Na+, Mg2+, K+, NH4
+, and Al3+ ions between the 2D Ti3C2Tx layers. In most cases, the cations intercalated spontaneously. The intercalation of some ions, notably Al3+, can be promoted electrochemically. We also report on intercalation-induced high volumetric capacitance of flexible Ti3C2Tx paper electrodes. This study provides a basis for exploring a large family of 2D carbides and carbonitrides in electrochemical energy storage applications using single- and multivalent ions.
References.
Lukatskaya, M.R., et al., Cation Intercalation and High Volumetric Capacitance of Two-Dimensional Titanium Carbide. Science, 2013. 341(6153): p. 1502-1505.
Separator Materials Influence on Supercapacitors Performance in Viscous Electrolytes
Authors: Tõnurist Kerli , Thomberg Thomas , Jänes Alar , Lust Enn 
Published: February 2020

It is well known that a high internal resistance limits the power capability of the supercapacitor (SC) and ultimately its application. In SCs a number of sources contribute to the internal resistance and are collectively measured and referred to as the equivalent series resistance. These are resistance of the electrode material, the interfacial resistance between the electrode and the current-collector, the ionic resistance of ions moving in small pores, the ionic resistance of ions moving through the separator and the electrolyte resistance. Separator has an effect on the ionic charge compensation rate between the positively and negatively charged microporous carbon electrodes soaked into the electrolyte solution. Therefore the molar conductivity of ions in the porous separator matrix is extremely important.
The aim of this paper was to study the influence of the separator material characteristics (chemical composition, morphology, thickness, porosity) on the performance of SCs at lower temperatures and viscous electrolytes. For that two different electrolytes were used: 1 M triethylmethylammonium tetrafluoroborate solution in dimethyl carbonate, ethylene carbonate and propylene carbonate mixture (TEMABF4 + DMC:EC:PC) with 1:1:1 volume ratio and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid. Temperature dependence study was performed with TEMABF4 + DMC:EC:PC electrolyte at the temperature range from +24 to -30 °C. To study the influence of the separator material characteristics different separator materials were used: commercially available separators prepared from cellulose (TF4425) and polypropylene (Celgard2400), and self-made separators, prepared by electrospinning method from poly(vinylidene fluoride) with different surface morphologies. Carbide-derived carbon electrodes, prepared from TiC at chlorination temperature T=950°C, were used. Our SCs were tested by cyclic voltammetry, constant power discharge and electrochemical impedance spectroscopy methods.
In given paper it will be discussed how high-frequency series resistance, phase angle, characteristic relaxation time constant and specific power values of SC depends on the separator parameters used. Also it will be shown that for the high power pulse generation systems, the properties of the separator material have to be carefully optimized and separator materials effect is highly important for the viscous electrolyte solutions based SCs and for systems working at lower temperatures.
Atomic Layer Deposition of Nanostructured Tunable Resistance Coatings: Growth, Characterization, and Electrical Properties
Authors: Mane Anil U. , Tong William M. , Brodie Alan D. , McCord Mark A. , Elam Jeffrey W. 
Published: February 2020

We have developed ALD method to synthesize nanocomposite coatings comprised of conducting, metallic nanoparticles embedded in an amorphous dielectric matrix. These films are nominally composed of M:Al2O3 where M= W or Mo, and are prepared using alternating exposures to trimethyl aluminum (TMA) and H2O for the Al2O3 ALD and alternating MF6/Si2H6 exposures for the metal ALD. By varying the ratio of ALD cycles for the metal and the Al2O3 components in the film, we can tune precisely the resistance of these coatings over a very broad range (e.g. 1011-104 Ohm-cm). These films exhibit Ohmic behavior and resist breakdown even at high electric fields of 107V/m. Moreover, the self-limiting nature of ALD allows us to grow these films inside of high aspect ratio substrates and on complex, 3D surfaces.
To investigate the ALD growth mechanism for the nanostructure composite films we employed in-situ quartz crystal microbalance (QCM), quadrupole mass spectrometry, and Fourier transform infrared (FTIR) absorption spectroscopy studies. For M:Al2O3 films, QCM showed that the metal ALD inhibits the Al2O3 ALD and vice versa. Despite this inhibition, the relationship between metal content and metal ALD cycle percentage was close to expectations. Depth profiling X-ray photoelectron spectroscopy showed that the M:Al2O3 films are uniform in composition and contained Al, O, and metallic Mo or W as expected, but also presence of moderate F and C. Attempts were also made to investigate the TMA as reducing precursor for MF6 and resulted in similar kind of resistive coatings but very significant F and C which shows influence on microstructure of the layers. Cross-sectional transmission electron microscopy (XTEM) revealed the film microstructure to be metallic nanoparticles (~1-2 nm) embedded in an amorphous matrix. The transport properties of these M:Al2O3 were studied as function of ratio of metal to Al2O3ALD cycles.
We have utilized these nanocomposite coatings to functionalize capillary glass array plates to fabricate large-area MCPs suitable for application in large-area photodetectors. In addition, we have applied these films to serve as charge drain coatings in MEMS devices for a prototype maskless electron beam lithography tool, permitting high resolution electron beam patterns without charging artifacts. Here we will discuss the ALD growth, characterizations, and applications of ALD tunable resistive coatings.
Merits of Batch ALD
Authors: Dingemans Gijs , Jongbloed Bert , Knaepen Werner , Pierreux Dieter , Jdira Lucian , Terhorst Herbert 
Published: February 2020

In this presentation, we provide an overview of the merits and applications of batch ALD in a vertical furnace. In addition, a number of common perceptions related to cycle time, films specs and batch processing in industry will be examined more closely.
Batch ALD offers a significant cost-per-wafer reduction compared to clustered single-wafer tools for a range of existing and emerging materials and applications. We present results on cycle time reduction to 20 s and below for ALD Al2O3 and TiN processes without significantly impacting uniformity, resistivity and step coverage. How purge and precursor flows influence the deposition process will be shown by combining experiment and simulation. The influence of deposition temperature and growth inhibition will be covered by presenting a thermal process for the deposition of AlN. A throughput of >50 wafers per hour was achieved for 10 nm films. For Si solar cells, the throughput and costs requirements are the most stringent. We will show that a platform of 4 reactors with automated handling for square solar wafers can reach 4800 wafers/hour (5 nm Al2O3) with remarkably low TMA consumption.
With the workhorse materials being TiN and Al2O3 and applications as diverse as metal gates in logic, trench capacitor electrodes, capacitor dielectrics, barrier layers and passivation films, batch ALD has firmly established itself at device manufacturers and foundry sites. Prospects for emerging markets such as MEMS, solar and LED will be discussed.
Challenges with Industrialization of Atomic Layer Deposition of Silicon Nitride
Authors: Hausmann Dennis , Henri Jon , Sims Jim , Kelchner Kathryn , Janjam Sathish , Tang Shane 
Published: February 2020

Scaling of next generation logic and memory semiconductor devices requires conformal thin films on high aspect ratio features at low deposition temperatures (<500ºC). Atomic layer deposition (ALD) is an ideal method for depositing these films and is currently being used in high volume manufacturing (HVM) to deposit high-k dielectric materials (HfO2, ZrO2, etc.) as well as the more traditional dielectrics silicon oxide (SiO2) and silicon nitride (SiNx). With the notable exception of silicon nitride, all of these films can be deposited at sufficiently low temperatures to satisfy the integration requirements while maintaining reasonable throughput and cost. In the HVM environment, silicon nitride ALD has historically been deposited in large furnaces operating at high temperatures, and although both plasma and thermal deposition of silicon nitride have been reported at low temperatures1-2, translation of these low temperature R&D films into HVM films has been challenging.
In this presentation, we discuss some of the challenges faced with addressing the requirements associated with bringing low temperature ALD SiNx into HVM, which include achieving high wafer throughput and low per wafer cost, while simultaneously keeping the resistance of the film to multiple downstream etches and cleans, which may include exposure to hydrofluoric acid (HF). Generic to all ALD processes is the high cost of the precursors relative to traditional chemical vapor deposition (CVD); in the case of SiNx, this is exacerbated by the relative low “reactivity to cost ratio” of available silicon precursors. Cost can partially be addressed with chlorosilane precursors, but the chlorine byproducts create challenges with deposition chamber materials and effluent management. Low reactivity of the silicon precursors poses challenges with respect to process design; the choice of spatial ALD vs. temporal ALD and isobaric vs. non-isobaric deposition sequences affects the final cost and throughput. Lastly, the use of plasmas in ALD poses challenges for achieving isotropic film properties over the complex topography on today’s semiconductor substrates.
References:
1. H. Goto, K. Shibahara and S. Yokoyama, Applied Physics Letters,
68, 3257 (1996).
2. J. Klaus, A. Ott, A. Dillon and S. George, Surface Science Letters,
418, L14 (1998).
Self Assembled Metamaterials Formed via Plasma Enhanced ALD of Ag Thin Films
Authors: Prokes S. M. , Glembocki Orest J. 
Published: February 2020

Plasma enhanced atomic layer deposition (PEALD) of Ag thin films using Ag(fod)(PEt3) as the precursor has been investigated. Although a regular film of Ag does not have any plasmonic activity, when silver is grown by PEALD, it exhibits unexpected plasmonic behavior, shown in Fig.1 characterized by the Surface Enhanced Raman (SERS) intensity. We show that these films consist of a mosaic structure (inset, Fig. 1) characterized by 2D Ag islands separated by very narrow air gaps (<8nm), which are parallel and extend down to the substrate. These parallel air gaps are an inherent property of the PEALD film, and the source of the plasmonic behavior. We have modeled the ALD-Ag film using FDTD E-M simulations, representing the film as a ring shaped air gap in Ag. The result of the model is shown in figure 2 where we display spatial maps of the electric fields at the resonance wavelength above the film and in cross section. The maps show a very strong confinement of optical fields in the gaps with an enhancement >10x. When PEALD Ag is combined with an active SERS material, such as dielectric core nanowires, the SERS enhancement can be enhanced by > 100x. We have also calculated the time evolution of these fields and have found that the confined plasmonic fields persist long after the excitation pulse. These results indicate that the ALD-Ag is a metamaterial with unique optical constants.
Since the air gaps are critical to the plasmonic behavior of this material, we will also discuss the effect of surface modification of the Ag PEALD. This was achieved by examining the effect of Ag oxide removal by H2 plasma as well as by ALD deposition of Al2O3, where the conformal nature of the coverage is critical. Ellipsometry data indicate a blue shift of the plasmonic resonance with the widening of the air gap (achieved by oxide removal) and with the addition of 2 cycles of Al2O3, which result in the lowering of the refractive index with the addition of the Al2O3. We will discuss the source of this blue shift and show how ellipsometry combined with electric field simulations can be used to obtain detailed chemical information on the surface and in the air gaps of this material, which would not be possible by experiment alone.
5minutes TSV Filling
Authors: Funaahashi Chikara , Kondo Kazuo , Yokoi Masayuki , Okamoto Naoki , Saito Takeyasu 
Published: February 2020

1.
Introduction

TSV(Through Silicon Via) is promising interconnection for the next generation smartphone, driving assistance and medical care system because of its ability of high speed image processing and low energy consumption. Conventional TSV filling requires several 10min. to hour because of applying small current of less than 10mA/cm2. This long time electrodeposition prevents TSV realization. We have achieved TSV filling within 5min. and the details will be presented.

2.Results

1.We have used via of diameter of 6μm and 25μm.
2.High current density of 90mA/cm2 is possible to apply without void formation by adopting the PR-current wave form.
3.Di-allyl amine type additive has been used.
4.Fig.1 shows the via filled witnin 5min.. We are further seeking for 1min. TSV filling in order to spread the low cost TSV process world wide.
References

K.Kondo, J. Electrochem. Soc. 2009 156(12): D548-D552

K.Kondo, J. Electrochem. Soc. 2005 152(11): H173-H177
Plating through Hole with High Throwing Power Using Dual Levelers
Authors: Hsu Chia-Fu , Dow Wei-Ping , Huang Su-Mei 
Published: February 2020

In recent year, the technology evolution of wireless networks promoted the development of multifunctional pad, computers and mobile phones. The circuit density of density electron product increased as function increased. As a result, the reliability of electron products was more and more important for high density interconnect (HDI) tendency. The copper electroplating process for high throwing power of plating through holes and the thin surface layer with filling via technology were key process for HID. In this paper, copper electroplating formulas that were composed of dual levelers were studied for plating through holes with high throwing power (TP). The base plating solution contained CuSO4, H2SO4, chloride ions, polyethylene glycol (PEG), bis (3-sulfopropyl) disulfide (SPS). When leveler A was added in the base plating solution, it resulted in a smooth surface, which looked like a mirror, but its TP was not good. When leveler B was added to the base plating solution, it enhanced the TP of the plated through hole. However, the board surface was rougher than that adding leveler A. Both leveler A and leveler B could not lead to smooth surface and good TP simultaneously. Interestingly, when both leveler A and leveler B were simultaneously added in the base plating solution, they not only enhanced the TP of the plated through hole but also made the board surface smooth and bright. These results show that chemical interaction can achieve unexpected functional plating.
Key words： High throwing power, high density interconnection, plating through hole and dual levelers.
Development of Glyoxylic Acid Based Electroless Copper Deposition on Ruthenium
Authors: Inoue Fumihiro , Philipsen Harold , van der Veen Marleen , Armini Silvia , Van Huylenbroeck Stefaan , Struyf Herbert , Shingubara Shoso , Tanaka Tetsu 
Published: February 2020

High aspect ratio through Si via (TSV) has received much attention as a process integration route to reduce stress build up around the TSV, leading to a small keep-out zone where device performance is impacted. High aspect ratio TSV requires alternative barrier and seed process, because physical vapor deposition (PVD) is facing difficulties yielding continuous layer in such structures. Combining the excellent conformality of ELD in high aspect ratio TSV and atomic layer deposition of barrier and liner, is seen as a potential process route [1]. Glyoxylic acid is a non-toxic reducing agent for ELD-Cu on Ru [2]. In previous work, we found that the nucleation mechanism is catalyst reaction [2]. In this paper, the different anodic reaction of formaldehyde and glyoxylic acid on Ru was compared by polarization analysis. Furthermore, the purity was evaluated after adding stabilizer in the ELD bath. The demonstration of deposition in TSV was performed using 3 × 50 µm TSV.
Figure 1 shows polarization analysis of glyoxylic acid and formaldehyde on Ru and PVD-Cu as a reference. All the measurements showed anodic oxidation. It indicates that the driving force of anodic oxidation of glyoxylic acid and formaldehyde is catalysis of Ru and Cu. Although the anodic oxidation of glyoxylic acid on Ru was weaker than formaldehyde, glyoxylic acid showed similar potential on Ru (-0.63 V) and Cu surface (-0.68 V) at -0.01 mA/cm2. They were -0.63 V on Ru and -0.83 V on Cu for the case of formaldehyde.
Furthermore, we found that 2,2’-bipyridyl worked as stabilizer, brightener and suppressor in the glyoxylic acid based bath. Figure 2 shows surface morphology, roughness and purity of ELD Cu using various concentrations of 2,2’- bipyridyl. The roughness and the purity of copper films improved by adding 2,2’-bipyridyl in the bath. The high purity of Cu might help to reduce void generation during the annealing process after filling. Figure 3 shows cross sectional TEM images of TSV after ELD on Ru. The ELD layer was defect free and worked as a seed layer for electrodeposition of copper. The advantage of depositing a conformal seed layer is that it also reduces the total Cu overburden, which is to be removed by CMP.
Reference
[1] F. Inoue, H. Philipsen, A. Radisic, S. Armini, Y.Civale, S. Shingubara, and P. Leunissen Journal of The Electrochemical Society, 159 (7) D437-D441 (2012)
[2] F. Inoue, H. Philipsen, A. Radisic, S. Armini, Y. Civale, P. Leunissen, M. Kondo, E. Webb, and S. Shingubaraba, Electrochimica Acta
100 (2013) 203– 211