bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Anhydrous Hydrazine Delivery for Low Temperature Silicon Nitride Passivation of Sige(110)
Authors: Alvarez Daniel , Spiegelman Jeffrey , Holmes Russell , Ramos Chris , Kummel Andrew , Edmonds Mary , Sardashti Kasra , Wolf Steven 
Published: February 2020

New high mobility channel materials such as SiGe, Ge, and InGaAs create difficult thermal constraints on Metal-Nitride deposition, where limits range from 300-400C. It is necessary to: limit atomic diffusion; prevent undesirable phase transitions, strain relaxation and defect formation. Feasibility for low temperature hydrazine (H2NNH2) ALD was reported by George.3 In addition, a new technology that is capable of generating and delivering stable and highly concentrated anhydrous hydrazine gas has been developed by RASIRC.

A thin layer of silicon nitride or silicon oxynitride can act as a diffusion barrier or channel passivation layer prior to dielectric deposition in FinFets or MOSFETs. When employed as a channel passivation layer, further oxidation with anhydrous peroxide leaves Si-N-OH termination, thereby providing good nucleation for High K deposition (Figure 1). This study focuses on developing <400C silicon nitride ALD process. STM/STS and XPS are employed to characterize SiNx film growth on Si0.5Ge0.5(110) (Figure 2). HfO2 is then grown on a Si-N-OH functionalized surface. Electrical characterization of MOSCAP structures has been obtained will be compared to other passivation methods such as ammonia plasma.

Figure 1
(Invited) Atomic Layer Deposition for Catalyst “Bottom-up” Synthesis
Authors: Lu Junling 
Published: February 2020

Catalyst synthesis with precise control over the structure of catalytic active sites at the atomic level is of essential importance for the scientific understanding of reaction mechanisms and for rational design of advanced catalysts with high performance. Such precise control is achievable using atomic layer deposition (ALD). ALD is similar to chemical vapor deposition (CVD), except that the deposition is split into a sequence of two self-limiting surface reactions between gaseous precursor molecules and a substrate. The unique self-limiting feature of ALD allows conformal deposition of catalytic materials on a high surface area catalyst support at the atomic level. The deposited catalytic materials can be precisely constructed on the support by varying the number and type of ALD cycles. As an alternative to the wet-chemistry based conventional methods, ALD provides a cycle-by-cycle “bottom-up” approach for nanostructuring supported catalysts with near atomic precision [1, 2].
In this presentation, the capability of achieving precise control over the particle size of monometallic nanoparticles by ALD is emphasized. The possibility of the preparation of single-atom metal catalysts by ALD at elevated temperatures will be discussed [3]. For supported bimetallic catalyst synthesis, I will show the challenges of combing two metal ALD processes to form bimetallic nanoparticles synthesis. Then our recent the strategy developed for selective metal-on-metal ALD for precise synthesis of supported bimetallic catalysts while excluding monometallic formation are particularly highlighted [4, 5]. In the final part of my presentation, I will focus on oxide ALD on metals for precise synthesis of nanostructured metal catalysts, therein, I will discuss the methods of tailoring the catalytic performance of metal catalysts including activity, selectivity and stability, through selective blocking of the low-coordination sites of metal nanoparticles, the confinement effect, and the formation of new metal-oxide interfaces [6, 7].

References

(1) J.L. Lu, J.W. Elam, P.C. Stair, Acc. Chem. Res. 46 (2013) 1806-1815.
(2) J.L. Lu, J.W. Elam, P.C. Stair, Surf. Sci. Rep. 2016, doi:10.1016/j.surfrep.2016.1003.1003.
(3) H. Yan, H. Cheng, H. Yi, Y. Lin, T. Yao, C.L. Wang, J.J. Li, S.Q. Wei, J.L. Lu, J. Am. Chem. Soc. 2015, 137, 10484-10487
(4) J.L. Lu, K.B. Low, Y. Lei, J.A. Libera, A. Nicholls, P.C. Stair, J.W. Elam, Nat. Commun. 2014, 5 3264.
(5) H.W. Wang, C.L. Wang, H. Yan, H. Yi, J.L. Lu, J. Catal. 2015, 324, 59-68.
(6) J.L. Lu, B. Fu, M.C. Kung, G. Xiao, J.W. Elam, H.H. Kung, P.C. Stair, Science 2012, 335, 1205.
(7) H. Yi, H.Y. Du, Y.L. Hu, H. Yan, H.-L. Jiang, J.L. Lu, ACS Catal. 2015, 5, 2735-2739.
Atomic Layer Deposition of Iridium Oxide Thin Films on Tungsten and Si Substrates
Authors: Zhang Kai , Lin Pengtao , Chen Xin , Baumgart Helmut , Bradas James 
Published: February 2020

Both Iridium and Iridium oxide thin films have been extensively investigated for their various applications. For Ir, it is a potential optical material in Fresnel zone, X-ray microchannel plates, inductive grid filters. On the other hand, iridium Oxide films can be used as a reference electrode and PH measurment in the field of biology environment and the food, nuclear, gas and oil industry due to their low resistivity, high transmittance, biocompatibility and good oxygen diffusion barrier properties [1,2].
The Atomic layer deposition (ALD) is considered as a half reaction of a chemical vapor depositon (CVD), where diferent ALD chemical precuresors are alternatively introduced into an ALD reaction chamber. The self-limiting surface reactions in each ALD cycle consequently result in precise layer thickness control, stoichiometry, composition, uniformity of large area on the substrate. ALD also can be used to deposit conformal film onto very complex substrate or template surfaces. In addition the ALD thin films can be deposited at low growth temperature. Therse are the advantageous properties of ALD which make it more competitive and promising.
In this work, the irdium oxide films were grown on Si and tungsten substrates by ALD using (Ethylcyclopentadienyl) (1, 5-cyclooctadien) iridium (C14H19Ir) and H2O/O2 as precursors for iridium and oxygen, respectively. The C14H19Ir was heated to 50 oC, while the H2O and O2 precursors remained at room temperature. The ALD for growth temperature was varied over a range of various temperatures in order to determine the ALD process window. The iridium oxide thin films were subsequently annealed at 700 oC for 1 hour in a furnace under O2 atmosphere. In this study we report successful synthesis of IrO2 films on tungsten metal substrates and native oxide covered Si wafers. Detailed physical characterization of ALD Iridium oxide thin films has been performed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), UV-VIS-NIR spectrometer.
References:

J. Hämäläinen, E. Puukilainen, M. Kemell, L. Costelle, M. Ritala and M. Leskelä, Chem. Mater. 21 (20), 4868 (2009).

T. Aaltonena, M. Ritalaa, V. Sammelselgb and M. Leskeläa, Journal of The Electrochemical Society, 151(8) G489 (2004).

Figure 1
Electrochemical Behavior and Analysis of Organic Additives in Cobalt Damascene Baths
Authors: Pavlov Michael , Lin Danni , Shalyt Eugene , Yan Xiaodong 
Published: February 2020

The copper dual damascene process has been used in semiconductor manufacturing since it was introduced by IBM in mid-1990. Since then, copper interconnects shrunk dramatically following the principles of Moore’s law. Currently, there are questions regarding the extendibility of the copper dual damascene flow as the IC industry moves beyond the 10 nm node. Copper interconnects are becoming more compact at each node, causing an increase in the resistance-capacitance delay. Furthermore, voids that occur in heavily scaled vias severely impact yield. Leading semiconductor manufacturers are exploring novel metallization methods to solve these issues. One way to solve the problem is to identify metallization alternatives that provide resistance benefits over conventional technology without compromising reliability and yield. Cobalt is considered as a potential replacement candidate for copper.Cobalt plating baths typically contain cobalt salt, boric acid, and organic additives . We have recently developed new analytical techniques for complete analysis of cobalt damascene plating baths.
Electrochemical methods are used to study behavior and analyze multiple organic additives present in cobalt plating baths , while other bath components can be effectively analyzed with traditional titration and/or spectroscopic methods.
Fig. 1 shows the effects of commercial Suppressor and Accelerator additives used for cobalt plating. The voltammograms indicate decreased plating rate when Suppressor additive is injected into the VMS electrolyte. VMS stands for Virgin make-up solution, which contains only inorganic components. The injection of Accelerator into the electrolyte with Suppressor causes increased plating rate. Fig. 2 shows response curves of Suppressor and Accelerator. All responses are reproducible and allow accurate determination of organic additives in plating baths. This article will also reveal the effects of other bath components on the plating properties of cobalt. We will also present statistical results of electrochemical analysis of both organic additives.

Figure 1
UV Laser Annealing Effect on Mechanical Properties of Boron Doped Amorphous Carbon Films As Hardmasks
Authors: Youn Chulmin , Yang Jaeyoung , Lee Sungwoo , Hur Ginyung , Choi Taekjib 
Published: February 2020

The hard forms of amorphous carbon (a-C, diamond like carbon) include hydrogenated amorphous carbon (a-C:H) and tetrahedral amorphous carbon have raised interest as coating materials. Recently, boron doped amorphous carbon films have been studied as hardmask materials. The hardmasks are utilized to fabricate advanced semiconductor devices, including dynamic random access memory (DRAM) and vertical NAND flash memory. As decreasing of feature sizes on DRAM and NAND, the hardmask materials need to exhibit a high etch selectivity with low internal stress and good mechanical strength. In this work, we have prepared boron doped amorphous carbon film deposited with the fixed B2H6 flow rate as a function of the process temperature using plasma enhanced chemical vapor deposition (PECVD). Boron has been widely known efficient dopant for passivating the oxidation of various carbon materials. We investigated the physical and optical properties of film with the refractive index, hardness and chemical bonding configuration. Especially, the effect of ultraviolet (UV) laser annealing on the hardness was studied using nano-indentation. UV annealing caused a change of chemical bonding configuration, i.e., sp2/sp3 bonding ratio and C-H bonds, through analysis of the Fourier transform-infrared (FT-IR) and RAMAN spectrum. UV annealed boron doped amorphous carbon thin films exhibited an enhanced hardness, which leads to high etch selectivity. Our results could provide a route to high etch selective hardmask materials development.
A Silicon Hollow Graphene Nanoshell Li-Ion Anode Composite Material
Authors: Banek Nathan A , Hays Kevin Alan , McKenzie Kevin R. , Wagner Michael J 
Published: February 2020

The Li-ion battery provides the majority of powertrain energy for today’s electric vehicles (EVs). The usable range of EVs is largely limited by the Li-ion storage capacity in a Li-ion cell. In addition to low range, most EVs require 4 - 12 hours of charge time. Silicon, a Li-alloy alternative anode, has much greater gravimetric and volumetric capacities compared to graphite (3579 mAh/g vs. 372 mAh/g and 8335 mAh/cm3 vs. 818 mAh/cm3 for Li15Si4 vs. LiC6). In addition to the increase in capacity, Si is nontoxic, highly abundant, and inexpensive. Despite these advantages, the volumetric expansion of LixSi and poor electrical conductivity of Si makes developing a pure silicon anode with reasonable cycle life a seemingly insurmountable challenge. Composite electrodes of Si and C could represent the next-generation of Li-ion anodes for EVs. Hollow graphene nanoshells (HGNS) are a conductive graphitic carbon ~50 nm in diameter that can charge in minutes and have cycle lives of over 1000 cycles with minimal fade making them a promising support material for silicon nanostructures of higher capacity. Utilizing a facile low-temperature solution synthesis method, silicon was synthesized onto the HGNS to produce Si/HGNS composites in high yield and purity. The electrochemical performance of the composite material had a reversible capacity of ~3500 mAh/g Si (1400 mAh/g composite) after a C/20 formation cycle with 80% first cycle Coulombic efficiency. At an increased rate of C/2, a reversible capacity of ~2800 mAh/g Si (1100 mAh/g composite) is achieved with stable cycling performance. Utilizing this solution synthesis method, efficient mixing of Si with HGNS can produce Li-ion anode composites greater than 3 times the capacity of graphite with stable performance at charging rates required for upcoming EV powertrains.
Investigating the Influence of Transition Metal Composition on High-Voltage Cathodes Performance By Using Magnetic Susceptibility
Authors: David Lamuel , Sefat Athena S , Cakmak Ercan , Sheng Yangping , Li Jianlin , Wood David L , Daniel Claus , Mohanty Debasish 
Published: February 2020

High-voltage cathodes are indispensable to enable the high-energy-density batteries. This work demonstrates the effect of Ni/Mn composition on structure of pristine and cycled layered Li-Ni-Mn/Al-Co oxide (NMC and NCA) during high-voltage operation (4.75V vs. Li). Particle morphology and elemental composition of all material was investigated by using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) analysis. Among the various materials NMC622 had the best uniformity in particle size at ~10um while the other materials ranged from ~5-10um. X-ray diffraction (XRD) spectra of the as-obtained powders showed little variation in the structure of layered oxide with different transition metal ion compositions. Temperature dependent magnetic susceptibility results show that NMC622 (with 60% Ni) is layered with less magnetic ordering which was very similar to that of NCA811 (80% Ni) while NMC442 (40% Ni) showed strong magnetic ordering, which suggests exchange of strong magnetic interaction among transition metal ions in NMC442 material. The structural differences that were observed from magnetic susceptibility results were correlated with the electrochemical performance. The detailed pristine structure and structural evolution in layered oxides varying the Ni concentration in the light of magnetic susceptibility will be presented.
High Capacity and High POWER Ncm/Graphite Lithium ION Battery Using Microgrid® Expanded Metal Current Collectors
Authors: Hart John 
Published: February 2020

To achieve better sustainable power application of LiNi1/3Co1/3Mn1/3O2/graphite lithium ion battery, new cell structures using Microgrid® expanded metal current collectors were studied. By adopting the Microgrid® foil for cathode electrodes, the performance of LiNi1/3Co1/3Mn1/3O2 electrodes was significantly improved at high rate discharge at both room and low temperature. Scanning electron microscopy was carried out to reveal coating features of Microgrid® cathode electrodes. The loading density of active materials can be increased by the pore structure, and the 10C capacity retention of Microgrid® electrode is 25.8% higher than that of a conventional electrode after 100 cycles, and nearly doubled for the initial discharge at 10°C. There is the potential for enhancement of cell performance using Microgrid® foils in place of conventional foils with LiNi1/3Co1/3Mn1/3O2 cathode and graphite anode. The Microgrid® full cell shows 209.0% increase of capacity with respect to conventional cells of Al and Cu foils for 10C after 100 cycles and keeps the retention rate 12% higher than the latter. Microgrid® foils can potentially be applied to other electrode materials which are suffering from capacity fade at high C-rates and at higher loading densities.
Ternary Cathode Materials Prepared By Induction Sintering Incorporated with Carbon Coating Technique for High Performance Li-Ion Batteries
Authors: Hsieh Chien-TE 
Published: February 2020

Lithium-ion battery has become the front-runner among rechargeable-battery technologies, having found applications in industries as diverse as portable electronics and electric vehicles (EVs) [1,2]. Recently, a number of attempts have been made to partially substitute Ni with other elements such as Co and Al doping. Among the resulting cathodes, LiNi0.8Co0.15Al0.05O2 (LNCA) is considered as one of the promising alternatives to replace LiCoO2 owing to its higher specific capacity and better environmental friendliness [3,4]. Generally, solid-state calcination was carried out under oxygen-containing atmosphere at 700–900°C for 15 hr. To shorten the growth period, this work proposes an efficient method of preparing LNCA cathode material by using induction sintering incorporated with carbon coating technique. The electrochemical performance of C-coated LNCA cathodes was well characterized by cyclic voltammetry (CV) and charge-discharge cycling. This study aims at examining the possibility of induction sintering route for preparing C-coated LNCA cathode materials for high-performance Li-ion batteries in practical or industrial applications.

We have successfully investigated the electrochemical performance of LNCA cathodes, using CV and charge-discharge cycling at 0.1−5C. An efficient induction route was adopted to synthesize LNCA powders at 700°C within a shorter calcination period (3 h), as compared with traditional heating methods. The as-prepared layered C-coated LNCA crystals possessed a low degree of cation mixing with highly hexagonal ordering. For 0.1C charge-discharge cycling, the discharge capacity of LNCA cathode could attain as high as 201 mAh g-1, and there was an increased capacity of 10.3% as compared with the fresh one. On the basis of the experimental results, the C-coated LNCA cathode remained higher capacity retention of 88.1% after 50 cycles at 1C. Accordingly, the induction route offered a promising pathway to commercially synthesize high-crystalline LNCA cathode materials for high-performance Li-ion batteries, favoring the application of EVs in the near future.
Influence of LiFePO4 Electrode Structure on Electrochemical Property
Authors: Yasumiishi Hirofumi , Yamaya Ryuta , Kitagawa Takao , Nakabeppu Tetsuya 
Published: February 2020

１．Introduction

Well known as safety, non-toxicity and remarkable thermal stability, LiFePO
4
(LFP) is one of a promising candidate for the cathode material of large size lithium ion batteries. However, LFP is also known as the material with poor electrochemical property at low temperature. In order to improve the low temperature properties of LFP, several attempts were made to control the particle size and the morphology of LFP particle to increase the diffusion in solid and the surface reaction area.
1

）

On the other hand, along with the increase of LFP’s specific surface area, the problems arised for the manufacturing of the electrode. The problems are the increase of the amount of binder needed and the LFP agglomeration which leads to the increase of the surface roughness of the electrode. In this research, we have studied the influence of the LFP’s primary and secondary particle size and the morphology of the secondary particle to improve the electrochemical properties.

２．Experimental

LFP was synthesized by a hydrothermal process. Spherical secondary particle with the size ranging from 10 to 30 μm in diameter was observed from the spray-drying of the LFP slurry. The electrode slurry mixing ratio was LFP:AB:PVdF=90:5:5 wt.%. After the slurry was coated on Al foil current conductor, it was vacuum dried under @120℃ for 12h、and pressed by a load of 200kgf. The cross-section image of the obtained electrode was observed by SEM. The particle size of the secondary particle was observed with particle size distribution measurements. The electrochemical properties were measured with pouch cell (anode：Li4Ti5O12 electrode, separator：porous polypropylene, electrolyte：1M LiPF6/EC:DEC=1:1 +VC2wt%)

３．Result

The relationship between LFP’s secondary particle size and Output – Direct Current Resistance (DCR) was shown in Fig. 1. The smaller the secondary particle size, the DCR decreased. The porous structure of the LFP’s electrode was thought to have a correlation to the electrochemical characteristics.
Fig.2 shows the cross-sectional SEM images of the electrode which showed the different structure for the electrode manufactured with different particle sized LFP. The bigger the secondary particle size, the bigger the vacant spaces present inside the electrode and the small secondary particle was enclosed in the large secondary particle. The non-uniform structure was observed for the electrode made with large secondary particle compared with the uniform structure made with the small secondary particle. The main factor of DCR increase for the large secondary particle size was thought to relate to the non-uniformity of secondary particle structure and electrode structure.
The relationship between the electrode structure, the secondary particle shape and the electrochemical properties will be studied further.
Ref. 1)　A. Yamada, S. C. Chung and K.Hinokuma , J. Electrochem. Soc., 144, p. A224 (2001)

Figure 1
A Novel Technique to Evaluate the Adhesion Property Between Ceramic Coated Layer and Separator Using Saicas
Authors: Gong Seokhyeon , Lee Yunju , Yeon Daeyong , Lee YongMin , Ryou Myung-Hyun 
Published: February 2020

Polyolefin-based microporous membrane has been widely used as a separator for lithium-ion batteries (LIBs), where they impede an internal short between positive and negative electrodes. Consequently, as the large-scale LIBs targeting electric vehicles (EVs) and energy storage systems (ESSs) is attracting the consumers’ interests, the development of safety enforced separators is getting important.
To achieve this goal, the surface coating based on inorganic ceramic particles Al2O3, SiO2, MgO, CaCO3, and etc. have been widely used to improve the mechanical and the thermal properties of the separators. However, the detachment of ceramic composites from the separator surface, which happens during separator preparation and cell assembly process, can cause serious problems in safety and cell performance of LIBs.
Unfortunately, however, there is no quantitative manner to examine the adhesion strength between ceramic composite layer and the separator surface yet. Here in, we introduced a Surface and Interfacial Cutting and Analysis System (SAICAS) to fulfil this purpose. Contrary to the traditional peel-off technique, SAICAS can measure the adhesion strength at a specific depth of coating of operator. Thus, SAICAS can compare adhesion properties in a systematic manner.
We measured the adhesion strength between the ceramic coating layer and the separator, and moreover, the adhesion strength inside the coating layer. Furthermore, we could compare the adhesion strength measured via traditional peel-off test technique. Finally, we investigated the adhesion strength of ceramic coating layer as a function of types and composite ratio of polymeric binder.

Acknowledgement

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2014R1A1A1005861).