bluuebunny/crossref_metadata_2025_split huggingface dataset:
ALD W Metal Gate CMP
Authors: Yang Tao , Xu Qiang , Lu Yihong , Yue Zhang , Xu Jing , Wang Guilei , Cui Hushan , Li Junfeng , Yan Jiang , Zhao Chao 
Published: February 2020

Beyond 32nm node, gate last integration scheme had become a mainstream because it ensures the thermal stability of high-kand metal gate stack by applying the metal gate after the high temperature source/drain activation anneal. During HKMG gate last CMOS integration, metal gate chemical and mechanical planarization (CMP) is an indispensable and key process step. Al metal gate is firstly introduced from 32nm node by Intel, which brought new process challenges for Al filling and correspondent CMP. We adopted W as metal gate using atomic layer deposition (ALD) method, besides of ALD W ideal fill capability, compatibility with traditional W CMP is also taken into account.
Different ALD W layers were prepared using B2H6 base and SiH4 base. Removal rate, surface roughness and electrochemical characteristic in W slurry were examined for two types ALD W. The removal rate of B2H6 base ALD W was high than that of SiH4 base. RMS of ALD W with SiH4 and B2H6 base were all less than 1nm after CMP. The adhesion of SiH4 base ALD W between W and barrier layer was stronger than that of B2H6 base ALD W. B2H6 base ALD W has better filling ability than that of SiH4 base ALD W for small size gate trench. Compared with single base ALD W filling metal gate, B2H6 base ALD W filling with SiH4 base ALD W pre-treatment was more benefit to decrease metal gate dishing after CMP process.
Effect of Some New Organic Polymers As Green Corrosion Inhibitors for Metals in Different Media
Authors: Branzoi Florina , Branzoi Viorel , Stanca Angela 
Published: February 2020

Pure metals and alloys react chemically/electrochemically with corrosive medium to form a stable compound, in which the loss of metal occurs. The compound so formed is called corrosion product and metal surface becomes corroded. Among the several methods of corrosion control and prevention, the use of organic corrosion inhibitors is very well known.
Using the microwaves energy new organic polymers were synthesized by radicalic polymerization. These new organic compounds have anticorrosive and antiscale properties and for this reason, were used for cooling water systems protection. The inhibition activity analysis of these new organic polymers was made by assuming that the mechanism of inhibition by organic molecules is chemisorptions and that the energetic of the corrosion process per se is unaffected by the addition of substituents on the parent compound. We presume that, these new organic polymers inhibit corrosion of carbon steel by a protective mechanism, forming insoluble iron complexes and repairing the porous oxide layers. The methods employed were potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy (SEM) and metallurgical microscopy techniques. The addition of the organic inhibitors led in all the cases to inhibition of the corrosion process. The inhibition efficiency was high in all the studied cases. The corrosion parameters obtained from polarization curves and from EIS spectra are in good concordance and point out the inhibitory action of these new organic polymers. The adsorptions of the organic compounds on the carbon steels surface obeyed Langmuir’s isotherm. Further characterization using Fourier transform infrared spectroscopy (FT-IR) demonstrates the adsorption of organic inhibitors and the formation of corrosion products on the carbon steels and the brass surface.
The inhibition process was attributed to the formation of the adsorbed film on the metal surface that protects the metal against corrosive agents. The EIS measurements have confirmed this protection and pointed out the formation of adsorption layers on the electrode surface.
Layered 2D Electrode Architecture for High-Power Lithium Ion Microbatteries
Authors: Shah Ankita , Kotz Sharon , Abraham K.M. , Somu Sivasubramanian , Busnaina Ahmed 
Published: February 2020

The power density of a lithium ion battery is predominantly limited by poor ionic and electronic pathways in the battery electrodes. To overcome these limitations, we have fabricated positive electrodes composed of a two-dimensional (2D) layer-by-layer electrode architecture using electrophoretic deposition. In this architecture, alternating layers of multi-walled carbon nanotubes (MWNT) and active lithium metal oxide nanoparticles are electrophoretically assembled onto a current collector. Each active metal oxide nanoparticle is precisely placed to make intimate contact with the conductive MWNT layers, eliminating all other electrode additives such as carbon black and polymeric binder (figure 1). Lithium manganese oxide nanoparticles (LiMn2O4, 300nm) are used as a model active material while MWNT are used as the scaffold. These multilayer electrodes demonstrate excellent rate capability up to 10C and cycling stability for over the 100 cycles tested (figure 2) in a Li/liquid electrolyte/LiMn2O4 cell. We observe that the electrode capacity per cm2increases linearly with the number of stacked layersat a rate of 0.06 mAh/per layer. Therefore, the capacity per footprint area can be increased by increasing the number of stacked layers. These multilayer electrodes are fabricated at room temperature and atmospheric pressure, and the assembly time per layer is less than 60 seconds.
As the number of layers is increased, the dependence of the electrode morphology on rate performance and cycle life is studied though galvanostatic cycling, cyclic voltammetry, electrochemical impedance spectroscopy and physical characterization techniques such as atomic force microscopy (AFM) and scanning electron microscopy (SEM). Multi-layer electrodes with higher capacity active materials such as the lithium-rich layered nickel-manganese-cobalt oxide will also be fabricated to further increase the capacity per footprint area of the microbattery [1, 2].

Acknowledgment: Financial support for this work was provided by the Department of Defense.
1. Thackeray, M., Kang, SH., Johnson, CS., Vaughey, JT., Benedek, R., and Hackney, SA., Li2MnO3-stabilized LiMO2 (M = Mn, Ni, Co) electrodes for lithium-ion batteries. Journal of Materials Chemistry, 2007. 17: p. 15.
2. W.C. West, J.S., M.C. Smart, B. V. Ratnakumar, S. Firdosy, V. Ravi, M. S. Anderson, J. Hrbacek, E. S. Lee, and A. Manthiram, Electrochemical Behavior of Layered Solid Solution Li2MnO3-LiMO2 (M=Ni, Mn, Co) Li-Ion Cathodes with and without Alumina Coatings. Journal of the Electrochemical Society, 2011. 158: p. 7.
Electroless Deposition: History, Status and Future Directions
Authors: Djokic Stojan S. 
Published: February 2020

Electroless deposition of metals, oxides, salts and other compounds is very important for many industrial and technological applications. These sophisticated processes have been used in different applications throughout many centuries, even though they were not recognized as such.
Based on the archeological discoveries some of the electroless deposition processes e.g. gold and silver were used in the early Mediterranean civilizations. Reduction of Ni(II) ions to the elemental nickel with hypophosphite was first discovered by Wurtz in 1846 [1]. Liebig discovered the reduction of Ag(I) to Ago, using the formaldehyde as a reducing agent [2]. In 1948, Brenner was the first who described proper conditions for the electroless deposition of nickel using hypophosphite as a reducing agent [3]. Significant developments in this area occurred in the second half of the 20th century and until now [4,5]. Metals of interest include of all the metals and alloys which can be electrodeposited from the aqueous solution i.e. Ni, Cu, Ag, Au, Pd etc, with particular attention given to nickel, copper, gold and silver.
Although many electroless depositions of nickel, cobalt, copper, silver, gold or similar are used in different industrial processes, there are many aspects of these processes that are not yet fully understood. It is well established that these processes are electrochemical by the nature, however, the mechanisms of the reactions governing the electroless deposition are not yet generally accepted by the researchers.
In this presentation a historical overview of the electroless processes used throughout centuries until present days will be given. Then, a classification of different electroless processes i.e., galvanic deposition, autocatalytic deposition and contact deposition will precisely be defined. Mechanisms of the electroless deposition and future directions for the electronic, biomedical, energy device, automotive and aero-space applications will be discussed.
Refernces:

A. Wurtz, C.R. Acad. Sci. Paris, 18 702 (1884); 21 149 (1845).

B. Liebeg, Ann. Chim et Phar. 14 140 (1835).

A.Brenner, G.E.Riddell, Proc.Am.Electropl.Soc., 33 16 (1946).

G.O. Malloy, J.B. Hajdu, Electroless Plating: Fundamentals and Applications, AESFS, Orlando, Florida, 1990.

S.S. Djokić, Electroless deposition of metals and alloys, Modern Aspects of Electrochemistry, No. 35, Ed. B. E. Conway, R.White and J.O’M Bockris,. pp.51-120, Kluwer Academic/Plenum Publishers, N.Y 2002.
Porous Conducting Membranes and Their Application in Vanadium Flow Battery
Authors: Li Xianfeng , Zhang Huamin 
Published: February 2020

The vanadium flow battery (VFB) has received widely attention due to its attractive features for large scale energy storage. One of the central problems that hinder the commercialization of VFB is the high cost and low selectivity of currently used perfluorinated membranes (Nafion). Although the non-perfluorinated hydrocarbon polymers like sulfonated or quaternary ammoniated aromatic polymers are widely investigated, these membranes often suffer from poor chemical instability which is proved to be induced by the introduction of ion exchange groups. Recently, we reported the application of porous membranes in VFB1. The idea is based on separating vanadium ions from protons via pore size exclusion. The new design and concept can potentially overcome the traditional restriction from ion exchange membranes and provide more materials option. Followed our idea, different kind of porous membranes separators were explored and investigated in VFB. Quite impressive progress was achieved via optimizing the membrane materials and morphology.
In this presentation, the current status of VFB porous membranes, including morphology control, structure-relation will be discussed in detail.

References

[1] Hongzhang Zhang, Huamin Zhang, Xianfeng Li, Zhensheng Mai, Jianlu Zhang,
Energy & Environmental Science

2011, 4 (5), 1676 – 1679

[2] Xianfeng Li, Huamin Zhang*, Zhensheng Mai, Hongzhang Zhang, Ivo Vankelecom,
Energy & Environmental Science,

2011, 4 (4), 1147 – 1160
Detection of Organic Molecules Using Conducting Materials
Authors: Chahma M'hamed , Enagala Sravya 
Published: February 2020

Surface modification allows the immobilization of a variety of organic molecules and biomolecules such as peptides, proteins and DNA on electrode surfaces. The systems commonly used for surface immobilization are the covalent linkers S-Au and C-N. By reduction of thiols, disulfides and diazonium salts, organic motifs have been deposited on gold and carbon surfaces.
Our strategy is based on the deposition of conducting materials as an intermediate between the electrode and chiral sites that can detect molecules via hydrogen bond formation (Scheme 1). Using cyclic voltammetry, we found that the capacitive current of the chiral surface (1) decreased by 30 % once the chiral electrode is interacting with target molecules (2). The hydrogen bond formation has been characterized by NMR and IR.
Sensitive Electrochemical NO Sensors: Towards Measurement of Nitric Oxide on Primary Epithelial Cell Models
Authors: Bose Tiyash , Bomberger Thomas , Bayachou Mekki 
Published: February 2020

Nitric oxide is an important physiologic metabolite implicated in both health and disease states. Accurate determination of NO in tissues and cells is of paramount importance. The major challenges with NO measurement are its short half-life and often low nanomolar concentrations in tissues. Electrochemical tools provide a mean to accurately measure this analyte in confined environments using miniaturized probes. In the past, our lab explored electrodeposited alternate layers of ruthenium oxide nanoparticles and a conductive sulfur-containing polymer on carbon microelectrode fibers for catalytic determination of NO.
In this work, we explore the performance of combined reference/working electrodes modified with ruthenium oxide in the detection of nitric oxide with the goal to measure nitric oxide at the level of single or collective cultured cells. This is a preliminary work towards preparing a device capable to measure nitric oxide levels in a cystic fibrosis cell line model. It has been found that exhaled NO levels remains unchanged or reduced in cystic fibrosis patients unlike other inflammatory lung diseases like asthma where it increases. However it is not clear whether the lower NO levels in cystic fibrosis correlate with lowered production of this metabolite in the bronchial epithelium. It was shown that levels of nitrite and nitrate, the primary stable end products of NO metabolism increases in the breath condensate of patients with cystic fibrosis. We will present preliminary results of our ruthenium oxide modified combined electrodes and how they can be applied to the study of cystic fibrosis at the cellular level.
Optical, Nanomechanical and Electrochemical Sensing on a DVD Disc
Authors: Boisen Anja 
Published: February 2020

Our vision is to create a platform where optical, nanomecanical and electrochemical sensors can be integrated and read-out using the mechanics and the optics from DVDs and Blu-Rays. Integrating sensors on a disc allows us to use centrifugal microfluidis which has been developed for more than 50 years and which has proven to be a simple and powerful way to manipulate liquid samples without the need of external pumps [1]. As an example, serum can be separated from a whole blood sample in a few minutes by simply spinning the disc and allowing the cellular components to sediment.
Cantilever-like sensors have been integrated on a disc [2] and we now have a method of obtaining large amount of data – allowing us to do statistics on the measurements. Currently, we are studying the specific detection of biomarkers, such as suPAR [3]. Additionally, we try to implement optical microscopy on the spinning platform in order to study and count larger objects such as cells. In this way it will be possible to analyze a given sample for several parameters simultaneously.
Electrodes can also be integrated on the spinning platform [4] and hereby it is possible to perform electrochemical measurements at the same time as having the benefit of the centrifugal liquid handling. As an example it is simple to measure in flow conditions and to perform continuous cyclic voltammograms in different concentrations of electrolytes using built-in valves.
In conclusion, the merger of sensors and centrifugal microfluidcs combined with sensitive and compact read-out possibilities from optical pick-up heads makes it possible to realize full sample pretreatment and read-out in a both fast and compact manner.

References:

1. M. Madou et al., Lab on a CD, Annual Review of Biomedical Engineering, Vol. 8: 601-628, 2016
2. F.G Bosco et al., High throughput label-free platform for statistical bio-molecular sensing, Lab on a Chip, 11(14) 2411-2416, 2011
3. M. Bache et al., Nanomechanical recognition of prognostic biomarker suPAR with DVD-ROM optical technology, Nanotechnology 24 (44), 444011, 2013
4. A.L. Brøgger et al., Centrifugal microfluidic platform with real-time electrochemical detection, 224th Electrochemical Society Meeting, 2013
Unique Applications of Megasonic Energy to MEMS Single Substrate Wet Processes
Authors: Dussault Donald , Dragoi Viorel 
Published: February 2020

The use of non-standard materials (e.g. specific substrates or polymer materials) for MEMS applications impose a requirement for the development of new techniques for even well-established process steps. Acoustic energy in the MHz frequency range has been used in the semiconductor industry for various processes such as post CMP cleaning, pre-bond and pre-deposition cleaning as well as photoresist development and stripping.
The work presented in this paper is introducing two different types of applications of acoustic energy in Micro- Electro- Mechanical Systems (MEMS) manufacturing processes: photoresist processing and single wafer cleaning for high cleanliness applications (wafer bonding).
A single wafer spin processer with triangular-shape transducer, the MegPie®, was used for both resist processing and substrate cleaning. The transducer covers a sector of the wafer and is placed in proximity to substrate surface (fig. 1).
The small gap between transducer and substrate is filled with the required process fluid. The shape and positioning of the transducer assure optimal acoustic energy transfer to the process fluid resulting in high uniformity.
Acoustic energy was used in the past in photolithography for enhancing the uniformity of, and accelerate resist development process, initially in LIGA applications.
The new MEMS applications, particularly the ones based on microfluidic structures built in polymer layers coated on a substrate raised the demand of new photolithography processes able to resolve high aspect ratio structures. Such an optimized process addresses new coating/soft baking procedures, new UV exposure techniques as well as new development methods or new resist stripping procedures (fig. 2).
Substrate cleaning during a process flow plays a crucial role for the final success of the process. The use of acoustic energy in the megasonic range in either batch or single wafer configurations is known to significantly enhance the cleaning results.
Wafer bonding is one of the MEMs processes that is very sensitive to particle contamination and demands the use of high efficiency cleaning processes with good uniformity and repeatability.
In a different process flow, particle neutrality and high particle removal efficiency were demonstrated for single wafer cleaning of Si wafers prior to fusion bonding. Experimental results showing the benefits of using acoustic energy for enhanced photoresist development and single wafer cleaning will be presented.
Figure 1. Horizontal spinner chuck system with fluid delivery and MegPie® transducer.
Wafer Bonding for MEMS Vacuum Packaging
Authors: Dragoi Viorel , Pabo Eric 
Published: February 2020

Wafer bonding emerged into a powerful technology providing robust solutions for specific manufacturing challenges in Micro- Electro- Mechanical Systems (MEMS) fabrication. Various wafer bonding processes based on different physical and chemical principles can be used in MEMS manufacturing based on the desired level of performance.
Among the MEMS devices which are built using one or more wafer bonding steps the devices operating under vacuum raised new challenges for bonding-based fabrication: the need for achieving vacuum levels down to 10-4 mbar, long term stable, had to be accommodated.
From the broad range of wafer bonding processes only few are compatible with vacuum applications: fusion bonding, anodic bonding, glass frit bonding and metal-based bonding. The outgassing at the bonded interface or of the bonding layer material is extremely important for vacuum applications as a high level of outgassing has a significant impact on final vacuum level in manufactured device. Additionally it has to be considered that the inner surfaces of a device cavity are expected to outgas so this is another factor imposing the low outgassing amount requirement for bonding process and bonding surfaces.
The vacuum levels required would further restrict the process type for specific applications. Applications requiring high vacuum levels are very sensitive to any outgassing during bonding so in some cases a small amount of getter material may be used inside the device cavity in order to compensate for the inner surfaces’ outgassing.
This work reviews the principles of vacuum encapsulation using wafer bonding. Examples showing the suitability of each process for specific applications types will be presented.
A significant challenge in vacuum MEMS fabrication is the lack of analytical methods needed for process characterization or reliability testing. A short overview of the most used methods and their limitations will be presented. Specific needs to be addressed will be introduced with examples.
Increased Corrosion Resistance of Zinc Magnesium Aluminum Galvanised Coating through Germanium Additions
Authors: Mehraban Shahin 
Published: February 2020

Improvements in the corrosion resistance of hot dipped galvanised steel coatings have been brought about over the last 20 years through binary alloy additions such as Al and more recently ternary Mg additions [1], [2], to further improve corrosion resistance quaternary additions were made to a commercially produced Zn-Mg-Al (ZMA) alloy.
Corrosion performance of the ZMA alloy coating was shown to improve through the addition of a quaternary element, Germanium. This was added in the molten state and the alloy mixture was rapidly cooled to mimic the cooling rate of a galvanised steel production line.
The increased corrosion resistance can be attributed to microstructural changes in the alloy composition due to Ge addition while in the molten state. The proportion of the most active MgZn2 phase which has been shown to initiate the corrosion reaction in a ZMA alloy [3] was reduced thorough the formation of Mg2Ge crystals. The formation of crystal structures within the experimental alloy also increased the heterogeneous nucleation of the primary zinc phase.
The Scanning Vibrating Electrode Technique (SVET) was used to measure the rate of corrosion, anode life and zinc loss of the alloy samples. Phases present in experimental alloy were identified using SEM in conjunction with EDX analysis and a relationship was determined between the observed microstructural phases and the corrosion rates for varying Ge addition.
[1] D. A. Worsley, H. N. McMurray, J. H. Sullivan, and I. P. Williams, “Quantitative Assessment of Localized Corrosion Occurring on Galvanized Steel Samples Using the Scanning Vibrating Electrode Technique,” Corrosion, vol. 60, no. 5, pp. 437–447, May 2004.
[2] A. R. Marder, “The metallurgy of zinc-coated steel,” Prog. Mater. Sci., vol. 45, no. 3, pp. 191–271, Jun. 2000.
[3] J. Sullivan, S. Mehraban, and J. Elvins, “In situ monitoring of the microstructural corrosion mechanisms of zinc–magnesium–aluminium alloys using time lapse microscopy,” Corrosion Science, vol. 53, no. 6, pp. 2208- 2215, Jun. 2011.