bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of HKMG Stack Interface Engineer Applicable to 22nm/16nm Finfet Mosfet
Authors: Xiong WenJuan , Wang DaiHai , Yin Huaxiang , Zhang Yongkui , Cui Hushan , Luo Ying , Li Tingting , Jiang Haojie , Zhu Huilong , Li Junfeng , Yan Jiang , Zhao Chao 
Published: February 2020

Since Intel announced that they had made a great breakthrough in 22nm node[1][2]on May 4, 2011, FinFET Transistor structures had almost controlled CMOS technology beyond 22nm node. In this node, with the development of lithography, silicide process was switched to the back end. This huge change bring benefit to the formation of HKMG stack interface engineer. Before the silicide step switched, limited by the already formed silicide, the growth temperature of interfacial oxide layer couldn’t be higher than 600°C for NiSi unstability at high temperature, but now 800°C or 850°C will also be allowed. So we could adopt thermal oxide as HKMG stack interface layer.
In this paper, as interface layer of HKMG stack, chemical and thermal oxide were all studied. In 32nm/22nm node Bulk Planar CMOS technology, chemical oxide was grown through spraying DI water diluted Ozone on bare silicon substrate which was generally used in industry. It’s advantage was low thermal budget and the disadvantage was thermal unstability of Chemical ox during ALD HfOX growth. ChemOX would diffuse into HK dielectric, referred to Fig 1(b). It could also be observed very clearly at Si/ChemOX/RTCVD SIN structure , referred to Fig 2(b). From Fig 1(a) and Fig 2(a) , we had no doubt about the stability of thermal oxide interface layer. In this article, We chose three different thermal oxidation methods which were RTO, ISSG alone, ISSG with plasma nitridation[3][4]respectively. Considering the state of silicon substrate surface would severely affect the quality of ultrathin interface oxide layer, we also chose two different cleaning process which were HF 100:1 and BOE 100:1 last.
In conclusion, in order to improve HKMG stack characteristic in FinFET Transistor structures, different interface layer and cleaning process had been studied. Considering the thermal unstability of Chemical oxidation method currently used in industry, we plan to take high quality thermal ultrathin interface oxide into 22nm node and beyond.

References

[1] “Intel Reinvents Transistors Using New 3-D Structure”, http://ewsroom.intel.com/community /intel_newsroom/blog.
[2] “Roadmap for 22 nm and beyond” , H.Iwai, Volume 86, Issues 7–9, Microelectronic Engineering, 2009 .
[3] “Ultrathin DPN STI SiON liner for 40 nm low-power CMOS technology” Chan-Yuan Hu etc. Volume 54, Issue 5, Solid-State Electronics 2010 .
[4]“Plasma nitridation optimization of sub-15Å gate dielectrics” F.N. CUBAYNES etc. International Symposium on Silicon Nitride and Silicon Dioxide Thin Insulating Films, 28 April - 2 May 2003, Paris, France.
Lifting Defect Improvement of Plasma Enhanced Nitride
Authors: Yu Hyunkwan , Shin Dong Suk , Kang Sangkoo , Park Moonhan , Lee Nea-In , Ku Ja-Hm , Roh Yonghan 
Published: February 2020

ABSTRACT

Plasma enhanced nitride (PESiN) has been applied for various layers in semiconductor device such as spacer, etch stopping layer, strain layer, hard mask. In order to match with each function of PESiN, process condition should be well optimized in terms of etch rate, stress, uniformity. In addition, defects which might be caused during process should be controlled for manufacturability. In this paper, Bubble shaped lifting defects that were observed open by PESiN were investigated. According to study for various cases of PESiN lifting defect, methods to control lifting defect were defined.
Lifting defects were observed after compressive PESiN deposition which is one of the strain technologies [1] that tensile PESiN is applied for nMOS and compressive PESiN is for pMOS as a contact etch stop layer to improve device performance in figure 1. Lifting defects were detected in wide pattern and wafer edge region on nickel silicide by compressive stress of PESiN and low adhesion between PESiN and nickel silicide. Buffer oxide, tensile SiN and compressive stress were split to reduce lifting defect, which led to lifting defect free in the sum condition of buffer oxide 150°Ê, tensile SiN 100°Ê and 2.5GPa compressive stress in figure 2. However, since buffer layer caused degradation of stress effect, bevel etch was processed before compressive PESiN. It showed lifting defect free due to adhesion increase between PESiN and nickel silicide in figure 3. The other lifting defects were observed after processing high density plasma inter layer dielectric (HDPILD) on stopper PESiN. Hydrogen radicals were generated during HDPILD process and these hydrogen radicals could be captured between SiN and silicon, which caused lifting defect. According to split of SiN thickness, lifting defects were shown in the range of 30°Ê~40°Ê SiN thickness. In the other hands, thicker SiN than this range prevented hydrogen trapping to SiN sub and thinner SiN than this led to hydrogen passing out through SiN in figure 4. According to study of HDPILD dependency, high deposition rate without hydrogen condition showed lifting defect reduction in figure 5. Since initial HDPILD layer was thicker in high deposition rate, hydrogen trapping could be prevented more.
In this paper, lifting defects by compressive stress and hydrogen trapping were introduced. According to analysis of lifting defect mechanism, several reduction methods were investigated such as buffer layer, pre bevel etch, SiN thickness dependency, post hydrogen effect. These various methods will be helpful to solve this kind of lifting defect for manufacturability.
References
[1] ] J. Huang et al., Thin Solid Films., (2009), P. 5
Boosting Supercapacitor Performance of Carbon Fibres Using Electrochemically Reduced Graphene Oxide Additives. (Oral; The Main Work Has Been Published Online On Physical Chemistry Chemical Physics Lately)
Authors: Cao Yachang 
Published: February 2020

A kind of hybrid fibres as supercapacitor electrodes based on carbon fibres and graphene additives by a synchronous electrochemical reduction and deposition method was demonstrated. The electrochemically reduced graphene oxide coated carbon fibres (ERGO@CF) with only a small amount addition (~1 wt. %) of ERGO displayed excellent electrochemical performance in both aqueous and gel electrolytes. The superior capacitive performance could be attributed to the synergistic effect between wrinkled and porous ERGO sheets and highly conductive CFs.

Fig. 1(A) Schematic diagram of ERGO@CF. (B) Digital photograph of a home-made setup for continuous preparation of long ERGO@CFs. (C) (D) SEM image of ERGO@CF with gully-like porous structure of ERGO on the surface of CF.
In the electrochemically deposition process, GO sheets were gradually coated on the surface of CFs, meanwhile most of oxygen containing functional groups on GO sheets were removed, indicating that GO sheets were electrochemically reduced. The chemical structures of GO and ERGO were verified by Raman spectra and X-ray photoelectron spectroscopy (XPS).
The specific capacitance of an optimized single hybrid ERGO@CF fibre was measured to be as high as 22.6 µF cm-1 (10.3 µF cm-2) in 1 M Na2SO4 aqueous electrolyte at a scan rate of 10 mV s-1, which was around three orders of magnitude enhanced compared to pure CF. The hybrid fibre electrodes showed excellent capacitive stability after thousands of charge-discharge cycles.

Fig. 2(A) Cyclic voltammetry (CV) curves of a single ERGO@CF at different scan rates in aqueous electrolyte. (B) Galvanostatic charge-discharge curves of ERGO@CF at different current densities in aqueous electrolyte. (C) Ragone plot of a solid supercapacitor indicates that the energy density does not decrease significantly when the power density increases.
Solid supercapacitor that combined two ~250 hybrid ERGO@CF fibres together coated with gel electrolyte (PVA-H3PO4) was studied to possess a specific capacitance of up to 13.5 mF cm-1 (307 mF cm-2) at a current density of 0.05 mA cm-1. Meanwhile, the energy density did not decrease notably as the power density increased. The maximum power density of such a solid supercapacitor could reach 0.74 mW cm-1 (8.5 mW cm-2) and the maximum energy density was measured to be 1.9 µWh cm-1 (21.4 µWh cm-2), representing a relatively high values compared with similar fibre-like ones.
This fibre electrode material also offered advantages such as easy operation, mass production capability, mechanical flexibility and robustness, and could be easily mass-produced with the possibility to overcome the major hurdle in the development of large scale applications of graphene.
Improved Performance and Pt Reduction Technology in the Manufacturing of the MEA By Electro Spraying Process
Authors: Oh JI-Won , Na Hyunwoong , Nahm Sahn , Kim Yonghwan , Choi Hanshin 
Published: February 2020

The purpose of this study is reduction of platinum consumption without loss of performance. Electro-spraying process was selected owing to practicable mass production, direct deposition of catalyst electrode on membrane, and without Pt loss during manufacturing process. It was optimized experiments for the asymmetric MEA to Pt reduction having regard to the reaction kinetics, functional layer was applied as to do decreasing of the mass transport, and heat treatment was practiced for the stability of the electrode. That was applied to the asymmetrically MEA by electro spraying.
Using JM 40wt%. catalyst, distilled water, nafion ionomer, and isopropyl alcohol, catalyst ink was prepared with an appropriate combination ratio. Cathode was fixed Pt loading amount to 0.4mg/cm2 and then asymmetric MEA was experimented by placing anode variable in 0.4, 0.3, 0.2 and 0.15mg/cm2 respectively. Performance evaluation was compared with an atmospheric pressure conditions and an additional fuel pressure of 0.5bar. Experimental results from Anode 0.15/Cathode 0.4mg/cm2 loading amount at 0.7V was measured power density of the 580 mW/cm2 and maxpower was measured the 644mW/cm2.
Electrochemical Characterization of an Electroactive Ureidopyrimidinone Derivative, a Four Hydrogen Bond Array Containing a Dimethylaminophenylurea
Authors: Clare Laurie A. , Smith Diane K. 
Published: February 2020

Electron transfer reactions can be used to perturb the strength of hydrogen bonding interactions between organic molecules. When molecular redox centers are integrated onto hydrogen bond arrays, this combination can become a powerful tool for controlling binding strength in supramolecular complexes. Whether used for sensing devices, molecular machines or self-assembly, the strength of a hydrogen bond can also be enhanced simply by arrangement of hydrogen donor interactions (D) versus hydrogen acceptor interactions (A). Indeed, because of secondary interactions, dimerization constants of the DDAA 4 H-Bond array typically exceed that of the DADA 4 H-Bond array.1 By combining a DDAA 4 H-bond array such as Meijer’s ureidopyrimidinone1with an electroactive center such as the dimethylaminophenylurea, the strength of hydrogen bonding becomes tunable.
Cyclic voltammetry investigation, in nonaqueous solvents, of dimethylaminophenylurea (UHH), a DD 2H-bond array, show that without a guest present, there is one reversible oxidation wave in methylene chloride of one electron height. CV Digital simulations as well as UV-vis spectroelectrochemistry indicate a proton transfer from the radical species to the reduced U(H)H, followed by another electron transfer due to potential inversion to give the quinoidal cation, Scheme 1. With the integration of the dimethylphenylamino redox center, this mechanism would certainly complicate the dimerization of Meijer’s DDAA array.
Scheme 1. Proposed oxidation mechanism of UHH undergoing an overall one electron transfer due to proton transfer.
Due to the acidity of the urea NH that is part of the electroactive center, proton transfer could also occur as part of the electrochemistry associated with the DDAA dimer. We hypothesize that depending on the ratio of arrays substituted with an electroactive center versus those without, the DDAA sequence could change to a DDAD array. With all arrays containing an electroactive center the hydrogen bonding array would form an ADDA homodimer.
This presentation will cover cyclic voltammetry studies that includes concentration and scan rate dependence investigations on Meijier’ DDAA dimer equipped with a dimethyphenylurea electroactive center. Digital CV simulations and spectroelectrochemistry will be used to analyze experimental CV ‘s.
Figure 1. Meijer’s ureidopyrimidinone (Upy) 4 H-bond system without redox functionality as a DDAA homodimer.
Figure 2. Structure of the proposed heterodimer, DDAD array, as a result of half the concentration with an electroactive center and the other half without.
References
1.Beijer, F. H.; Sijbesma, R. P.; Kooijman, H.; Spek, A. L.; Meijer, E. W., Strong Dimerization of
Ureidopyrimidones via Quadruple Hydrogen Bonding. Journal of the American Chemical Society
1998, 120,
(27), 6761-6769.
Cerium Oxide Nanoparticles Decorated SAM Modified Gold Electrode for ROS Biosensing
Authors: Neal Craig J. , Saraf Shashank , Park Sanghoon , Das Soumen , Cho Hyoung J. , Seal Sudipta 
Published: February 2020

Informatics is a new and flourishing sector in biomedical engineering with biosensors playing a crucial, central role. Self-Assembled monolayer (SAM) based biosensors constitute a large portion of these due to their simplistic design and broad application. Herein we present a cerium oxide nanoparticle (CNPs) functionalized SAM biosensor for amperometric reactive oxygen species (ROS) detection. SAM-based biosensors often times employ enzymes to detect analytes. These sensors are limited to particular pH, salt concentration, and temperature conditions specific to normal conditions for the enzyme. Operation outside these conditions can cause irreversible protein denature and loss of sensation. It is well established that CNPs has unique oxidase like activity.[1, 2] Therefore, by using inorganic CNPs, this sensor is able to operate at adverse conditions without loss of sensitivity. The inorganic material also prevents phase interactions which could result in bio-fouling. The presented sensor is able to detect extremely low concentrations for H2O2 and with high selectivity. Bare gold electrode was used as a substrate and coated with an SAM of mercaptododecanoic acid (MDDA), a well-established SAM polymer. The carboxylic terminus of MDDA was used for CNPs conjugation. Cyclic voltammetry and chronoamperometric testing was performed in phosphate-buffered saline and potassium hexacyanoferrate, a well-known redox couple. Hydrogen peroxide was infused in micromolar concentrations for sensing. Comparison to bare gold electrodes shows orders of magnitude greater sensitivity to [H2O2] and significantly more defined analyte selectivity.
References:
1. Hirst, S.M., et al., Anti inflammatory Properties of Cerium Oxide Nanoparticles. Small, 2009. 5(24): p. 2848-2856.
2. Gaynor, J.D., et al., Enzyme-free Detection of Hydrogen Peroxide from Cerium Oxide Nanoparticles Immobilized on Poly (4-vinylpyridine) Self–Assembled Monolayers. J. Mater. Chem. B, 2013.
Catalytic Activity of PrNixCo1-XO3 - Graphene nanocomposites for Sustainable Energy Application
Authors: Schrandt Matthew , Kolla Praveen , Smirnova Alevtina 
Published: February 2020

Cobalt-containing perovskites ABO3 with praseodymium in A-site have been investigated as a possible candidate for cathode material for intermediate temperature solid oxide fuel cells. It was found that the conductivity of these compounds does not change significantly with temperature. At close to room temperatures they have conductivity similar to that at high temperatures (1580 S∙cm−1 at 50°C and 1031 S∙cm−1 at 1000°C).1 This could be favorable for the oxygen reduction reaction/oxygen evolution reaction (ORR/HER) catalytic activity while considering energy storage and generating devices, such as fuel cells or metal air batteries.
Pt catalysts are the leading catalysts for use in ORR.2 However, Pt is an expensive catalyst and with limited supply can not be considered a sustainable material for feasible application that is scalable in the economy. This calls for new solutions for catalyst materials that either mitigate the amount of Pt used in catalysts by developing hybrid catalysts, or to replace Pt altogether with a material with similar or better catalytic activity.
Praseodymium based pyrochlores (PrNixCo1-xO3-
d) with three concentration of Co ranging from x=0.1, 0.5, and 0.9 have been synthesized using a modified nitrate-glycine Pechini method and sintered at different temperatures, specifically 900°C and 1200°C. The XRD data shown in figure 1 indicates that the peaks responsible for the PrNixCo1-xO3-
d perovskite structure are present in the materials.1

The electrochemical performance of the perovskites sintered at 1200°C and tested in KOH (0.1M) demonstrated that PrNi0.9Co0.1O3-
d has the highest ORR activity in comparison to the two other perovskites. This activity gradually increases with an increasing ratio of cobalt to nickel at the B site.
The electrochemical performance for the samples with and without graphene in acidic (HClO4) and basic (KOH) solutions will be presented and discussed in terms of mass and catalytic activity in comparison to Pt/graphene as a baseline.
Fig. 1: XRD data PrNi0.5Co0.5O3-
d after 1200°C sintering.
Fig. 2: Cyclic voltammetry of PrNixCo1-xO3-
dfor x = 0.1 (solid line), 0.5 (dotted line), 0.9 (dashed line) in an oxygen purged KOH (0.1 M) solution.
REFERENCES:

1 S. Huang, Q. Lu, S. Feng, G. Li, C. Wang, J. of Power Sources
199,150 (2012).

2 W. Vielstich, H. Okokawa, and H.A. Gasteiger, Handbook of Fuel Cells: Fundamentals, Technology, and Applications, Wiley (2009).
Conductivity of Co-Ionic Composite electrolytes based on Oxygen-Ion and Proton Conductors
Authors: Park Jun-Young , Park Ka-Young 
Published: February 2020

Solid oxide fuel cells (SOFCs) have attracted as clean power sources because of their have high energy conversion and fuel flexibility. In particular, the operation of SOFCs at intermediate temperature (IT) has lots of advantages such as fast start-up, reduced fabrication cost, extensive materials choice, and extended durability. IT-SOFC operations can be accomplished with highly ionic conductive SOEs at the IT.
Recently, SOFCs employ oxygen-ion or proton conductors as solid oxide electrolytes (SOEs). SOFCs based on oxygen-ion conductors such as yttria-stabilized zirconia (YSZ) and rare-earth doped ceria (RDC) have extensively researched. Until now, the most widely used SOE is YSZ. The YSZ SOEs present sufficient oxygen ionic conductivity at high temperature of about 1000°C. On the other hand, RDC SOEs present high ionic conductivity of the same order of magnitude at the IT. However, RDC SOEs exhibits mixed ionic-electronic conduction behaviors due to the reduction of Ce4+ to Ce3+at reducing atmospheres. This causes electronic transport within the SOE, resulting in significant decreasing cell voltage.
Compared to oxygen conductors, SOFCs based on proton conductor such as yttrium-doped barium zirconate (BZY) and yttrium-doped barium cerate (BCY) have received attention as alternative IT-SOEs, lately. These perovskite-type oxides have high proton conductivity in humid hydrogen atmospheres at IT. In addition, the activation energy for ionic conduction is much smaller than the oxide ion conductor. However, BZY is hard to be sintered with low grain boundary conductivity. And BCY show poor chemical stability in atmospheres containing H2O and CO2.
Hence, in this work, composite SOEs, mixed with the oxygen-ion (e.g. RDC) and proton conductors (e.g.BZY), are studied for decreasing SOFC operating temperature. The conductivity of composite SOEs can be enhanced due to highly interfacial energy between oxygen-ion and proton conductors with extra defects by heterointerfaces of two materials.
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* Corresponding authors: jyoung@sejong.ac.kr (J.-Y. Park)
Use of Langmuir Blodgett Thin Films for Rectification in Energy Harvesting Applications
Authors: Sharma Saumya , Stefanakos Elias , Ram Manoj 
Published: February 2020

Tunnel diodes have been found suitable for use in high frequency rectification for energy harvesting applications in a rectenna. For tunneling to take place in a metal insulator metal diode for rectification at THz frequencies, an ultrathin pinhole free insulating layer must be deposited between the metal layers for the diode to operate with small turn on voltages.
Langmuir Blodgett (LB) thin film deposition is a useful technique that allows the deposition of conformal, uniform monomolecular layers with a precise control of thickness. Organic compounds such as Vinyl Stearate, 10-12 Pentacosadiynoic Acid and Porphyrin were considered for deposition onto a Nickel film and were later topped with a small metal contact to complete the metal insulator metal diode assembly.
Several characterization techniques were used to check the quality of deposition of the thin insulator film and to analyze its material properties. UV spectroscopy, atomic force microscopy and infrared spectroscopy techniques were utilized for this purpose. An electrochemical study was performed with 10-12 Pentacosadiynoic acid deposited using the LB method on an Indium Tin Oxide coated glass substrate. Along with these characterization results, the current voltage characteristics of the diode behavior as well as its suitability for detection or energy harvesting will also be reported.
An Extensive Computational Study of the Adsorption of Thiophene on Transition Metal Surfaces: Role of Van Der Waals
Authors: Rojas Tomas , Kara Abdelkader 
Published: February 2020

Van der Waals (vdWs) interactions play a significant role in the determination of the adsorption characteristics at the interface between a molecule and a substrate. In this study, self-consistent inclusion of vdW interactions in density functional theory provides a good perspective to understand the interaction between organic adsorbates and inorganic interfaces. We present the results of adsorption of thiophene (C4H4S) on various transition metal surfaces with the goal of comparing the performance of five different vdW functionals (optB86, optB88, optPBE, revPBE, rPW86). Seven metallic substrates (100) are used for our study; three coinage metals (Au, Ag, Cu) and four reactive metals (Pt, Pd, Rh, Ni). The results show that vdWs inclusion enhances the interaction for Ag ( 0.08 to 0.73 eV), Au (0.14 to 0.86 eV), Cu (0.12 eV to 0.77 eV), Ni(1.56 to 2.34 eV), Pt (1.6 to 2.51 eV), Pd (1.67 to 2.54), Rh (1.74 to 2.96 eV). In addition, we performed calculations for adsorption heights along with analysis of the electronic changes (charge transfer, changes in the d-band of the substrate, and change in the work function) to complement our understanding of these systems.
This work is funded by the U.S. Department of Energy Basic Energy Science under Contract No DE-FG02-11ER16243