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hfO_2 Gate Dielectrics for Future Generation of CMOS Device Application

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journal of Semiconductors 2004年第10期25卷 1193-1204页

作者： h.Y.Yu j.F.kang Ren Chi M.F.Li D.L.Kwong Silicon Nano Device Laboratory Department of Electrical & Computer Engineerin gNUSSingapore 119260SingaporeInstitute of MicroelectronicsPeking UniversityBeijing 100871ChinaSilicon Nano Device LaboratoryDepartment of Electrical & Computer Engineerin gNUSSingapore 119260SingaporeSilicon Nano Device LaboratoryDepartment of Electrical & Computer Engineerin gNUSSingapore 119260SingaporeInstitute of MicroelectronicsSingapore 117685SingaporeDepartment of Electrical & Computer EngineeringThe University of TexasAust inTX 78752USA

The material and electrical properties of hfO 2 hi gh-k gate dielectric are *** the first part,the band alignment of h fO 2 and (hfO 2) x(Al 2O 3) 1-x to (100)Si substrate and thei r thermal stability are studied by X-ray photoelectron spectroscopy and *** energy gap of (hfO 2) x(Al 2O 3) 1-x,the valence band offset, and the conduction band offset between (hfO 2) x(Al 2O 3) 1-x and the Si substrate as functions of x are obtained based on the XPS results .Our XPS results also demonstrate that both the thermal stability and the resist ance to oxygen diffusion of hfO 2 are improved by adding Al to form hf aluminat *** the second part,a thermally stable and high quality hfN/hfO 2 gate stack is *** changes in equivalent oxide thickness (EOT),gate leakage, and work function (close to Si mid-gap) of hfN/hfO 2 gate stack are demonstrat ed even after 1000℃ post-metal annealing(PMA),which is attributed to the super ior oxygen diffusion barrier of hfN as well as the thermal stability of the hfN/ hfO 2 ***,even without surface nitridation prior to hfO 2 depo sition,the EOT of hfN/hfO 2 gate stack has been successfully scaled down to les s than 1nm after 1000℃ PMA with excellent leakage and long-term reliability.T he last part demonstrates a novel replacement gate process employing a hfN dummy gate and sub-1nm EOT hfO 2 gate *** excellent thermal stability of the hfN/hfO 2 gate stack enables its use in high temperature CMOS *** e replacement of hfN with other metal gate materials with work functions adequat e for n- and p-MOS is facilitated by a high etch selectivity of hfN with respe ct to hfO 2,without any degradation to the EOT,gate leakage,or TDDB characteris tics of hfO 2.

关键词： hfO2 CMOS TDDB TEM XPS Al2O3 PMA

Effect of interlayer addition on microstructure and mechanical properties of NiTi/stainless steel joint by electron beam welding

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journal of Materials Science & Technology 2021年第2期61卷 16-24页

作者： h.Niu h.C.jiang M.j.Zhao L.j.Rong CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of ScienceShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China

NiTi/Stainless Steel(SS) sheets have been welded via a vacuum electron beam welding process, with three methods(offsetting electron beam to SS side without interlayer, adding Ni interlayer and adding Fe Ni interlayer), to promote mechanical properties of the Ni Ti/SS joints. The joints with different interlayers are all fractured in the weld zone near the Ni Ti side, which is attributed to the enrichment of intermetallic compounds including Fe2 Ti and Ni3 Ti. The fracture mechanisms of different joints are strongly dependent on the types of interlayers, and the joints without interlayer, adding Ni interlayer and adding Fe Ni interlayer exhibit cleavage fracture, intergranular fracture and mixed fracture composed of cleavage and tearing ridge, respectively. Compared with the brittle laves phase Fe2 Ti, Ni3 Ti phase can exhibit certain plasticity, block the crack propagation and change the direction of crack propagation. The composite structure of Ni3 Ti and Fe2 Ti will be formed when the Fe Ni alloy is taken as the interlayer, which provides the joint excellent mechanical properties, with rupture strength of 343 MPa.

关键词： NiTi Stainless steel Electron beam welding Interlayer Mechanical property

Trends and advances in the development of coal fly ash-based materials for application in hydrogen-rich gas production:A review

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journal of Energy Chemistry 2022年第10期31卷 485-512,I0013页

作者： kang Gao Maria C.Iliuta Department of Chemical Engineering Laval UniversityQuébecQC G1V 0A6Canada

Coal fly ash(FA),a valuable industrial solid residue generated from coal combustion,is composed of various metal oxides and has a high thermal *** that the coal-based energy will continue to account for a significant portion of global electricity generation in the coming years,the lack of effective management strategies exacerbates the threat of FA wastes to the surrounding environment and human *** a sustainable development,green and renewable hydrogen economy and CO_(2)capture efforts provide appealing opportunities to valorize FA as catalysts and/or sorbents due to their appealing physicochemical *** applications along with carbon neutrality are potential strategies to mitigate climate change crisis,but high processing costs(catalysts/sorbents)are challenging to realize this *** this context,the utilization of FA not only enhances industrial competitiveness(by reducing manufacturing costs),but also provides ecologically friendly approaches to minimizing this solid *** state-of-the-art review highlights a wide-ranging outlook on the valorization of FA as catalysts and sorbents for hydrogen-rich gas production via conventional/intensified processes(CO_(2)/h_(2)O reforming,ammonia decomposition,hydride hydrolysis).The fundamental physicochemical characterizations and hazards/utilization of FA,which significantly affect the FA's utilization in various fields,are first *** influence of several factors(like FA types and catalysis/sorption operation conditions)on the activity performance of FA-based materials is then discussed in *** critical review aims to open the window to further innovative ideas regarding the application of different FA residues in other catalytic and sorption processes.

关键词： Coal fly ash Catalyst/support high temperature CO_(2)sorbent Bifunctional material hydrogen production Conventional/intensified process

B-doped activated carbon as a support for a high-performance Zn-based catalyst in acetylene acetoxylation

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Green Energy & Environment 2022年第2期7卷 221-228页

作者： Fulong Zhu Mingyuan Zhu Lihua kang School of Chemistry and Chemical Engineering of Shihezi University ShiheziXinjiang832003China

A series of boron-doped(B-doped) catalysts with dissimilar mass ratios of boric acid and activated carbon(AC) were prepared by an impregnation method for acetylene *** introduction of a number of boron atoms activates the stable π electrons in AC,which not only enhances the electron transfer between Zn and the reactants,but also improves the adsorption ability of Ch_(3)*** the conversion rate of Ch_(3)COOh from 50% to 65% *** inductively coupled plasma(ICP) analysis confirmed the content of zinc approximately 7.3 wt% for both Zn/AC and Zn/0.02 B-AC-900 ***,X-ray photoelectron spectroscopy(XPS) analysis demonstrated that the introduction of boron changed the electron cloud density of Zn,and the strength of the Zn–O(from Ch_(3)COOh) bond was *** addition,temperature-programmed desorption(TPD) analysis revealed that the Zn/0.02 B-AC-900 catalyst enhanced the adsorption of Ch_(3)COOh and reduced the adsorption of C_(2)h_(2),thus the conversion rate of Ch_(3)COOh was increased.

关键词： boron catalyst adsorption

EFFECT OF GROUNDWATER TABLE CONTROL ON WATER SAVING IRRIGATIONSTRATEGIES IN ThE QINGTONGXIA IRRIGATION DISTRICT

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journal of hydrodynamics 2004年第2期16卷 166-175页

作者： WANGXiu-gui hOLLANDERSP.h.j. StateKeyLaboratoryofWaterResourcesandhydropowerEngineeringScience WuhanUniversityWu-han430072Chinae-mail.xgwang@wuhee*** InternationalInstituteforInfrastructural HydraulicandEnvironmentalEngineeringTheNetherlands

This paper focuses on the analysis of the effects of groundwater tablecontrol under different irrigation water amounts on the water and salinity balance and on cropyield. Two experimental areas, the Pingluo and huinong experimental sites, were selected to collectthe required data. The agro-hydrological model Soil-Water-Atmosphere-Plant (SWAP) was used toanalyse the water flows and salt transport processes for different groundwater levels and irrigationscenarios. Six scenarios, which resulted from different groundwater table regimes combined withdifferent irrigation amounts, were simulated. The results show that high ground-water tables due tothe excessive irrigation are the main cause of the large amount of drainage water and low cropyield; reducing irrigation water without a lower groundwater table will not lead to a largereduction of the drainage water, and will reduce the crop yield even more; to lower the groundwatertable is a good measure to control the drainage water and increase crop yield.

关键词： water saving irrigation field drainage saline water irrigation watermanagement

Transport properties of warm and hot dense iron from orbital free and corrected Yukawa potential molecular dynamics

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Matter and Radiation at Extremes 2017年第6期2卷 287-295页

作者： h.Y.Sun Dongdong kang Yong hou j.Y.Dai Northwest Institute of Nuclear Technology Xi'anShaanxi 710024PR China Department of Physics College of ScienceNational University of Defense TechnologyChangshaHunan 410073PR China

The equation of states,diffusions,and viscosities of strongly coupled Fe at 80 and 240 eV with densities from 1.6 to 40 g/cm^(3) are studied by orbital-free molecular dynamics,classical molecular dynamics with a corrected Yukawa potential and compared with the results from average atom model.A new local pseudopotential is generated for orbital free *** low densities,the Yukawa model captures the correct ionic interaction behavior around the first peak of the radial distribution function(RDF),thus it gives correct RDFs and transport *** higher densities,the scaled transformation of the Yukawa potential or adding a short range repulsion part to the Yukawa potential can give correct RDFs and transport *** corrected potentials are further validated by the force matching method.

关键词： Transport properties Orbital-free molecular dynamics Yukawa model Force matching

Thermoelastic Analysis of Non-uniform Pressurized Functionally Graded Cylinder with Variable Thickness Using First Order Shear Deformation Theory(FSDT) and Perturbation Method

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Chinese journal of Mechanical Engineering 2015年第6期28卷 1149-1156页

作者： KhOShGOFTAR M j MIRZAALI M j RAhIMI G h Faculty of Mechanical Engineering Tarbiat Modares University Department of Mechanical Engineering Faculty of Engineering Arak University Department of Mechanical Engineering Politecnico di Milano

Recently application of functionally graded materials（FGMs） have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

关键词： non-homogenous cylinder First order Shear Deformation Theory matched asymptotic method perturbation method functionally graded material

Incremental forming of free surface with magnesium alloy AZ31 sheet at warm temperatures

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中国有色金属学会会刊：英文版 2008年第A1期18卷 165-169页

作者： Y.h.jI j.j.PARK Department of Mechanical and System Design Engineering Hongik University

The formabilityof AZ31 sheet begins to increase drastically at 150℃.The incremental forming technique was thus applied to AZ31 sheet at 150℃to utilize the formability to its fullest capacity at the lowest possible temperature for forming applications.A surface scanning technique was used followed by the tool path generation to incrementally form an egg *** thorough examination of various tool paths,the surface was most successfully produced by forming an intermediate shape followed by a series of tool *** scale stickers were devised to improve the accuracy in the measurement of grid deformation.

关键词：金属材料数控成形加工 AZ31镁合金板材

Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

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journal of Rare Earths 2004年第Z2期22卷 153-156页

作者： D h jung B Park j j Lee School of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma