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Formation of High-quality Advanced High-k Oxide Layers at Low Temperature by Excimer UV Lamp-assisted Photo-CVD and Sol-gel Processing

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Chemical Research in Chinese Universities 2004年第4期20卷 396-402页

作者： YU j. j. Electronic & Electrical Engineering University College London

We have successfully demonstrated that high quality and high dielectric constant layers can be fabricated by low temperature photo-induced or -assisted processing. Ta_2O_5 and ZrO_2 have been deposited at t<400 ℃ by means of a UV photo-CVD technique and HfO_2 by photo-assisted sol-gel processing with the aid of excimer lamps. The UV annealing of as-grown layers was found to significantly improve their electrical properties. Low leakage current densities on the order of 10 -8 A/cm 2 at 1 MV/cm for deposited ultrathin Ta_2O_5 films and ca.10 -6 A/cm 2 for the photo-CVD ZrO_2 layers and photo-irradiated sol-gel HfO_2 layers have been readily achieved. The improvement in the leakage properties of these layers is attributed to the UV-generated active oxygen species O( 1D) which strongly oxidize any suboxides to form more stoichiometric oxides on removing certain defects, oxygen vacancies and impurities present in the as-prepared layers. The photo-CVD Ta_2O_5 films deposited across 10.16-cm Si wafers exhibit a high thickness uniformity with a variation of less than \{±2.0%\} being obtained for ultrathin ca.10 nm thick films. The lamp technology can in principle be extended to larger area wafers, providing a promising low temperature route to the fabrication of a range of high quality thin films for future ULSI technology.

关键词： Excimer lamp High-kdielectrics Thin film Chemical vapour deposition(CVD) Sol-gel processing

Indian plate paleogeography, subduction and horizontal underthrusting below Tibet: paradoxes, controversies and opportunities

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National Science Review 2022年第8期9卷 175-193页

作者： Douwe j.j.van Hinsbergen Department of Earth Sciences Utrecht University

The India–Asia collision zone is the archetype to calibrate geological responses to continent–continent collision, but hosts a paradox: there is no orogen-wide geological record of oceanic subduction after initial collision around 60–55 Ma, yet thousands of kilometers of post-collisional subduction occurred before the arrival of unsubductable continental lithosphere that currently horizontally underlies Tibet. Kinematically restoring incipient horizontal underthrusting accurately predicts geologically estimated diachronous slab break-off, unlocking the Miocene of Himalaya–Tibet as a natural laboratory for unsubductable lithosphere convergence. Additionally, three endmember paleogeographic scenarios exist with different predictions for the nature of post-collisional subducted lithosphere but each is defended and challenged based on similar data types. This paper attempts at breaking through this impasse by identifying how the three paleogeographic scenarios each challenge paradigms in geodynamics, orogenesis, magmatism or paleogeographic reconstruction and identify opportunities for methodological advances in paleomagnetism, sediment provenance analysis, and seismology to conclusively constrain Greater Indian paleogeography.

关键词： collision orogenesis subduction reconstruction Himalaya Tibet

Genome of Wild Mandarin and Domestication History of Mandarin

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Molecular Plant 2018年第8期11卷 1024-1037页

作者： Lun Wang Fa He Yue Huang jiaxian He Shuizhi Yang jiwu Zeng Chongling Deng Xiaolin jiang Yiwen Fang Shaohua Wen Rangwei Xu Huiwen Yu Xiaoming Yang Guangyan Zhong Chuanwu Chen Xiang Yan Changfu Zhou Hongyan Zhang Zongzhou Xie Robert M. larkin Xiuxin Deng Qiang Xu Key Laboratory of Horticultural Plant Biotogy (Ministry of Education) Huazhong Agricultural University Wuhan 430070 P.R. China Horticulture institute Hunan Academy of Agricultural Sciences Changsha 410125 P.R. China Fruit Tree Research Institute Guangdong Academy of Agricultural Sciences Guangzhou 510640 P.R. China Guangxi Key Laboratory of Citrus Biology Guangxi Academy of Specialty Crops Guilin 541000 P.R. China Institute of Citrus Science Research of Ganzheu City Ganzhou 341000 P.R. China

Mandarin （Citrus reticulata） is one of the most important citrus crops worldwide. Its domestication is believed to have occurred in South China, which has been one of the centers of mandarin cultivation for four millennia. We collected natural wild populations of mandarin around the Nanling region and cultivated landraces in the vicinity. We found that the citric acid level was dramatically reduced in cultivated mandarins. To understand genetic basis of mandarin domestication, we de novo assembled a draft genome of wild mandarin and analyzed a set of 104 citrus genomes. We found that the Mangshan mandarin is a primitive type and that two independent domestication events have occurred, resulting in two groups of cultivated mandarins （MD1 and MD2） in the North and South Nanling Mountains, respectively. Two bottlenecks and two expansions of effective population size were identified for the MD1 group of cultivated mandarins. However, in the MD2 group there was a long and continuous decrease in the population size. MD1 and MD2 mandarins showed different patterns of interspecific introgression from cultivated pummelo species. We identified a region of high divergence in an aconitate hydratase （ACO） gene involved in the regulation of citrate content, which was possibly under selection during the domestication of mandarin. This study provides concrete genetic evidence for the geographical origin of extant wild mandarin populations and sheds light on the domestication and evolutionary history of mandarin.

关键词： Citrus Citric acid Domestication Genome Wild mandarin

Application of CCD Cameras to Investigations of Mixing on Boundaries of a Thermal Plasma jet

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Plasma Science and Technology 2007年第6期9卷 743-746页

作者： j.HLINA j.SONSKY j.SLECHTA Institute of Thermomechanics Academy of Sciences of the Czech RepublicDolejskova 5182 00 Praha 8Czech Republic

Mixing of a thermal plasma jet with the surrounding atmosphere was studied using two CCD cameras （PCO SensiCam） situated detecting simultaneously the radiation of argon and nitrogen. The evaluation of image differences between two records showed that the location of regions on plasma jet boundaries characterised by stronger nitrogen radiation changes with the plasma flow rate. Close-to-laminar flow results in a small mixing rate and consequently low nitrogen optical emission on plasma jet boundaries. The increase of the flow rate leads to the formation of a relatively thick and stable layer on the boundaries characterised by strong nitrogen radiation. Further enhancement of the flow rate results in the formation of unstable regions of excited nitrogen molecules moving along the jet.

关键词： thermal plasma jet mixing CCD camera

Design,fabrication,characterization and reliability study of CMOS-MEMS Lorentz-force magnetometers

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Microsystems & Nanoengineering 2022年第5期8卷 17-41页

作者： j.j.Valle j.M.Sánchez-Chiva D.Fernández j.Madrenas Department of Electronic Engineering Universitat Politècnica de CatalunyaJordi Girona 1 i 3Edifici C408034 BarcelonaSpain Sorbonne Université CNRSLaboratoire de Recherche en Informatique(LIP6)UMR76064 place Jussieu75005 ParisFrance Institut de Física d’Altes Energies(IFAE) The Barcelona Institute of Science and Technology(BIST)Edifici Cn.Facultat Ciències NordUniversitat Autónoma de Barcelona08193 Bellaterra(Barcelona)Spain

This article presents several design techniques to fabricate micro-electro-mechanical systems(MEMS)using standard complementary metal-oxide semiconductor(CMOS)*** were applied to fabricate high yield CMOS-MEMS shielded Lorentz-force magnetometers(LFM).The multilayered metals and oxides of the back-end-of-line(BEOL),normally used for electronic routing,comprise the structural part of the *** most important fabrication challenges,modeling approaches and design solutions are *** that predict the Q factor,sensitivity,Brownian noise and resonant frequency as a function of temperature,gas pressure and design parameters are presented and validated in characterization tests.A number of the fabricated magnetometers were packaged into Quad Flat No-leads(QFN)*** show this process can achieve yields above 95%when the proper design techniques are *** CMOS not being a process for MEMS manufacturing,estimated performance(sensitivity and noise level)is similar or superior to current commercial magnetometers and others built with MEMS ***,typical offsets present in Lorentz-force magnetometers were prevented with a shielding electrode,whose efficiency is ***,several reliability test results are presented,which demonstrate the robustness against high temperatures,magnetic fields and acceleration shocks.

关键词： Lorentz magnetometer characterization

Fast Data Processing of a Polarimeter-Interferometer System on j-TEXT

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Plasma Science and Technology 2016年第12期18卷 1143-1147页

作者：刘煜锴高丽刘海庆杨曜高翔 j-TEXT Team Institute of Plasma Physics Chinese Academy of Sciences University of Science and Technology of China Institute of Fusion and Plasma Research School of Electrical and Electronic EngineeringHuazhong University of Science and Technology

A method of fast data processing has been developed to rapidly obtain evolution of the electron density profile for a multichannel polarimeter-interferometer system（POLARIS）on j-TEXT. Compared with the Abel inversion method, evolution of the density profile analyzed by this method can quickly offer important information. This method has the advantage of fast calculation speed with the order of ten milliseconds per normal shot and it is capable of processing up to 1 MHz sampled data, which is helpful for studying density sawtooth instability and the disruption between shots. In the duration of a flat-top plasma current of usual ohmic discharges on j-TEXT, shape factor u is ranged from 4 to 5. When the disruption of discharge happens, the density profile becomes peaked and the shape factor u typically decreases to 1.

关键词： fast data processing polarimeter-interferometer j-TEXT

Bulk and surface damages in complementary bipolar junction transistors produced by high dose irradiation

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Chinese Physics B 2018年第1期27卷 430-437页

作者： j Assaf Atomic Energy Commission Damascus Syria

Two complementary types NPN and PNP of bipolar junction transistors （BjTs） were exposed to higll dose of neutrons and gamma rays. The change in the base and collector currents, minority carriers lifetime, and current gain factor/3 with respect to the dose were analyzed. The contributions of the base current according to the defect types were also reported. It was declared that the radiation effect of neutrons was almost similar between the two transistor types, this effect at high dose may decrease the value of/3 to less than one. The Messenger-Spratt equation was used to describe the experimental results in this case. However, the experimental data demonstrated that the effect of gamma rays was generally higher on NPN than PNP transistors. This is mainly attributed to the difference in the behavior of the trapped positive charges in the SiO2 layers. Meanwhile, this difference tends to be small for high gamma dose.

关键词： bipolar junction transistors radiation effects surface damage bulk damage

Subpulse Drifting of PSR j1110–5637

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Research in Astronomy and Astrophysics 2022年第6期22卷 109-117页

作者： S.j.Dang L.H.Shang L.Lin Q.j.Zhi R.S.Zhao C.B.Wu Z.Y.You A.j.Dong j.T.Bai X.Xu D.D.Zhang H.Yang Q.W.Lin School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China School of Physics Science and Technology Xinjiang UniversityUrumqi 830011China

We report a detailed study of polarization characteristics and subpulse drifting in PSR j1110-5637 with the observations of the Parkes 64 m radio telescope at 1369 *** observations revealed that the trailing component of the pulse profile has obvious subpulse drifting,while the leading component has no subpulse *** the two-dimensional fluctuation spectrum(2DFS),we detected three distinct emission modes in the trailing component(modes A,B and C).The emission in mode A is chaotic and indistinguishable,while modes B and C have obvious subpulse *** vertical modulation periods P3of modes B and C are around the mean values of 12 P and 8 P,*** subpulse drifting of PSR j1110-5637 will expand the pulsar sample with multiple subpulse drifting rates,and this will help future systematic studies on the physical origin of the subpulse drifting phenomenon.

关键词： (stars:)pulsars general-(stars:)pulsars individual(PSR j1110-5637)-Stars

General aspects on structural integrity

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Chinese journal of Aeronautics 2019年第1期32卷 114-132页

作者： j.j.XIONG R.A.SHENOI School of Transportation Science and Engineering Beihang University Faculty of Engineering and Environment University of Southampton

This paper seeks to mark the fruitful collaborative research between scholars in the University of Southampton and Beihang University for last 25 years on structural integrity. Their efforts addressed some important issues in structural integrity such as fatigue and fracture behavior,fatigue load spectra, fatigue and fracture lifetimes, reliability-based service period, adhesively bonded composite patch repairs, Plain Woven Fabric(PWF) composites and composite *** advances in engineering approaches, experimental methods, numerical algorithms and understanding of failure mechanisms relating to structural integrity are highlighted. Probable limits(or drawbacks) are also discussed. This review provides an insight into the general aspects on structural integrity and constitutes a basis for pointers to the further works on structural integrity.

关键词： Composites Fatigue Fracture Reliability Repair Structural integrity