Design Guideline of Ultra Thin Body MOSFET

Simulation method is used to provide a guideline f or ultra thin body(UTB) MOSFET designs.Three important parameters of the UTB MOS FE T,i.e.the raised S/D height,Ge mole fraction of the Ge xSi 1-x gate,and the silic on body thickness,are comprehensively analyzed and optimized.The optimal region of feasible Ge mole fraction and the silicon body thickness for low operating po wer device are given.As the simulation results show that through changing Ge mole fraction coupl ed with the silicon body thickness tuning,UTB device with good performance can b e obtained.

Analysis on Dynamic Characteristics in Time Domain of Slider with Ultra Thin Spacing

With increasing recording density in computer hard disks,the flying height of the magnetic head becomes 10 nm or less.The numerical method of the control equations needs to be optimized consistently with the decrease of the flying height.The iterative process is usually divergent with traditional methods which cannot ensure the accuracy of the analysis results and the stability of numerical calculations.Firstly,a new scheme is presented to solve the ultra-thin lubricating control equations in this paper.The equilibrium equation is obtained by taking the Couette flow terms and time term as dominating terms in iterative process.Moreover,the weighting flow factor is introduced for the abrupt change of film thickness in order to reduce calculated deviation.Secondly,the rules for variation of flying pose of the magnetic head with time are obtained by the time domain analysis.The results show that the magnetic head can recover to the equilibrium position after being slightly influenced by outside disturbance.And the dynamic lubrication properties of the head suffer heavily from the vibrations in the height direction and fluctuation in the pitch direction.Finally,the analysis of the sine roughness-passing capacity of the head indicates that the head can surpass small sine waves and the equilibrium position can be retrieved after a period of decaying oscillation.The proposed research ensures the accuracy and stability of the numerical calculation of the control equations,and the dynamic characteristics and flying stability of a magnetic head is studied systematically.It can also be the theoretical basis for the analysis of the flight characteristics of the slider.

Comparative impact behaviours of ultra high performance concrete columns reinforced with polypropylene vs steel fibres

Polypropylene(PP) fibres have primarily used to control shrinkage cracks or mitigate explosive spalling in concrete structures exposed to fire or subjected to impact/blast loads, with limited investigations on capacity improvement. This study unveils the possibility of using PP micro-fibres to improve the impact behaviour of fibre-reinforced ultra-high-performance concrete(FRUHPC) columns. Results show that the addition of fibres significantly improves the impact behaviour of FRUHPC columns by shifting the failure mechanism from brittle shear to favourable flexural failure. The addition of steel or PP fibres affected the impact responses differently. Steel fibres considerably increased the peak impact force(up to 18%) while PP micro-fibres slightly increased the peak(3%-4%). FRUHPC significantly reduced the maximum midheight displacement by up to 30%(under 20°impact) and substantially improved the displacement recovery by up to 100%(under 20° impact). FRUHPC with steel fibres significantly improved the energy absorption while those with PP micro-fibres reduced the energy absorption, which is different from the effect of PP-macro fibre reported in the literature. The optimal fibre content for micro-PP fibres is 1% due to its minimal fibre usage and low peak and residual displacement. This study highlights the potential of FRUHPC as a promising material for impact-resistant structures by creating a more favourable flexural failure mechanism, enhancing ductility and toughness under impact loading, and advancing the understanding of the role of fibres in structural performance.

CO_(2) mineralization by typical industrial solid wastes for preparing ultrafine CaCO_(3): A review

Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.

Spatiotemporal mapping of(ultra‐)mafic magmatic mine areas:Implications of economic and political realities in China

The spatiotemporal extension/expansion of mine areas is affected by multiple factors.So far,very little has been done to examine the interaction between mine areas and political or economic realities.The(ultra‐)mafic magmatic mines in China played a specific role in supporting national development and providing an ideal research subject for monitoring their interrelationship.In this study,remote sensing and mining‐related GIS data were used to identify and analyze 1233(ultra‐)mafic magmatic mine area polygons in China,which covered approximately 322.96 km2 of land and included a V–Ti–Fe mine,a copper–nickel mine,a chromite mine,an asbestos mine,and a diamond mine.It was found that(1)the areal expansion of mines is significantly related to the mine types,perimeter,topography,and population density.(2)The mine area variation also reflects market and policy realities.The temporal expansion of the mine area from 2010 to 2020 followed an S‐shaped pattern(with the turning point occurring in 2014),closely related to iron overcapacity and tightened mining policies.(3)The complexity(D)of the mine area may reflect mine design and excavation practices.To be specific,lower D indicates early‐stage or artisanal/small‐scale mining,whereas higher D represents large‐scale mining.This study demonstrates that the detailed mapping of mine land can serve as an indicator to implement miningrelated market and policy changes.The(ultra‐)mafic mines area data set can be accessed at https://zenodo.org/record/7636616#.Y-p0uXaZOa0.

Xpert MTB/RIF Ultra对结核性脑膜炎的早期诊断价值

目的:评价Xpert MTB/RIF Ultra(Ultra)对结核性脑膜炎(TBM)的早期诊断价值。方法:对79例患者的临床资料进行分析,用Ultra、Xpert MTB/RIF(Xpert)、宏基因测序(mNGS)和分枝杆菌培养(MGIT)检测脑脊液(CSF)中的结核分枝杆菌。在临床诊断的基础上,分析各方法的检测性能和利福平药物敏感性。结果:Ultra的敏感度(56.4%)、曲线下面积(AUC值)和Kappa值(0.521)均高于MGIT(20%、0.600、0.236)、Xpert(40%、0.700、0.236)和mNGS(32.7%、0.664、0.352)。在31例Ultra阳性病例中,24例对利福平敏感,7例耐药性不确定。结论:与其他方法相比,Ultra检测脑脊液中结核分枝杆菌具有较高的敏感性。因此,Ultra可用于TBM的早期诊断。

Xpert MTB/RIF Ultra在儿童结核诊断中的应用价值

目的:探讨Xpert MTB/RIF Ultra在儿童结核诊断中的应用价值。方法:选取2010年1月—2022年12月山东省公共卫生临床中心收治的150例患儿作为研究对象。根据临床综合诊断确诊结果将结核病感染患儿纳入试验组(n=100),将非结核病感染患儿纳入对照组(n=50)。计算不同标本类型的敏感度、特异度、阴性预测值、阳性预测值和准确度,评价Xpert MTB/RIF Ultra检出利福平(RIF)耐药性的效能。结果:Xpert MTB/RIF Ultra的检测所有标本总敏感度为77.00%,特异度为96.00%;合并肺内标本敏感度为92.85%,特异度为96.29%,其中肺内标本中肺泡灌洗液敏感度最高为100.00%;合并肺外标本敏感度为77.55%,特异度为95.65%,其中肺外标本中淋巴结敏感度最高为100.00%。结论:不同标本类型中Xpert MTB/RIF Ultra对儿童结核的检出率差异较大,在诊断肺内结核标本时,检测肺泡灌洗液标本价值最高,在诊断肺外结核标本时,检测淋巴结标本价值最高。

An Empirical Direct Tunneling Current Expression for Ultra-Thin Oxide nMOSFETs

An empirical expression for the direct tunneling (DT) current is obtained.This expression can be used to calculate the DT current for nMOSFETs with ultra thin oxide when the oxide thickness is considered as an adjustable parameter.The results have good agreement with the experimental data.And the oxide thickness obtained is less than the value acquired from the capacitance voltage( C V )method.

A Novel Ultra-Thin Channel Poly-Si TFT Technology

A novel low temperature poly\|Si(LTPS) ultra\|thin channel thin film transistor (UTC\|TFT) technology is proposed. The UTC\|TFT has an ultra\|thin channel region (30nm) and a thick drain/source region (300nm). The ultra\|thin channel region that can result in a lower grain\|boundary trap density in the channel is connected to the heavily\|doped thick drain/source region through a lightly\|doped overlapped region. The overlapped lightly\|doped region provides an effective way for the electric field to spread in the channel near the drain at high drain biases, thereby reducing the electric field there significantly. Simulation results show the UTC\|TFT experiences a 50% reduction in peak lateral electric field compared to that of the conventional TFT. With the low grain\|boundary trap density and low drain electric field, excellent current saturation characteristics and high drain breakdown voltage are achieved in the UTC\|TFT. Moreover, this technology provides the complementary LTPS\|TFTs with more than 2 times increase in on\|current, 3.5 times reduction in off\|current compared to the conventional thick channel LTPS TFTs.

First-principles study and electronic structures of Mn-doped ultrathin ZnO nanofilms

The first-principles density functional calculation is used to investigate the electronic structures and magnetic properties of Mn-doped and N-co-doped ZnO nanofilms.The band structure calculation shows that the band gaps of ZnO films with 2,4,and 6 layers are larger than the band gap of the bulk with wurtzite structure and decrease with the increase of film thickness.However,the four-layer ZnO nanofilms exhibit ferromagnetic phases for Mn concentrations less than 24% and 12% for Mn-doping performed in the whole layers and two layers of the film respectively,while they exhibit spin glass phases for higher Mn concentrations.It is also found,on the one hand,that the spin glass phase turns into the ferromagnetic one,with the substitution of nitrogen atoms for oxygen atoms,for nitrogen concentrations higher than 16% and 5% for Mn-doping performed in the whole layers and two layers of the film respectively.On the other hand,the spin-glass state is more stable for ZnO bulk containing 5% of Mn impurities,while the ferromagnetic phase is stable by introducing the p-type carriers into the bulk system.Moreover,it is shown that using the effective field theory for ferromagnetic system,the Curie temperature is close to the room temperature for the undamped Ruderman-Kittel-Kasuya-Yoshida（RKKY） interaction.

Characteristics of Ultra-Thin Oxide pMOSFET Device After Soft Breakdown

The degradation of MOS transistor operation due to soft breakdown of the gate oxide is studied.Important transistor parameters are monitored under homogeneous stress at different temperature until the soft breakdown occurred.The output and transfer characteristic have small change after soft breakdown as the degradations of drain current and threshold voltage is continuous.However,the increment of gate leakage current increases abruptly after the soft breakdown.The analysis to the increment of gate leakage current after the soft breakdown shows mechanism of similar Fowler Nordheim(FN) tunneling current.

Experimental Investigation on Cooling/Heating Characteristics of Ultra-Thin Micro Heat Pipe for Electric Vehicle Battery Thermal Management

Due to the heat pipes’ transient conduction,phase change and fluid dynamics during cooling/heating with high frequency charging/discharging of batteries,it is crucial to investigate in depth the experimental dynamic thermal characteristics in such complex heat transfer processes for more accurate thermal analysis and design of a BTMS. In this paper,the use of ultra?thin micro heat pipe(UMHP) for thermal management of a lithium?ion battery pack in EVs is explored by experiments to reveal the cooling/heating characteristics of the UMHP pack. The cooling performance is evaluated under di erent constant discharging and transient heat inputs conditions. And the heating e ciency is assessed under several sub?zero temperatures through heating films with/without UMHPs. Results show that the pro?posed UMHP BTMS with forced convection can keep the maximum temperature of the pack below 40 °C under 1 ~ 3 C discharging,and e ectively reduced the instant temperature increases and minimize the temperature fluctuation of the pack during transient federal urban driving schedule(FUDS) road conditions. Experimental data also indicate that heating films stuck on the fins of UMHPs brought about adequate high heating e ciency comparing with that stuck on the surface of cells under the same heating power,but has more convenient maintenance and less cost for the BTMS. The experimental dynamic temperature characteristics of UMHP which is found to be a high?e cient and low?energy consumption cooling/heating method for BTMSs,can be performed to guide thermal analysis and optimiza?tion of heat pipe BTMSs.

Research on the Influence of Cutting Condition on the Surface Microstruct ure of Ultra-thin Wall Parts in Ultrasonic Vibration Cutting

In many fields of high-tech industry the ultra-t hi n wall parts are employed. In this paper the experiments were carried out to dis cuss the surface microstructure of the camera’s guided drawtube by applying ult rasonic vibration cutting device to the traditional lathe. The influence rule of the cutting condition on the surface roughness was put forward, which was drawn by comparing the ultrasonic cutting with the common cutting by use of the cemen ted carbide tool and the polycrystalline diamond (PCD) tool. The test results sh owed that the ultrasonic cutting performs better than the common cutting in the same condition. According to the test results analyzing, the surface characteriz ation is influenced clearly by the rigidity of the acoustic system and the machi ne tool, as well the setting height of the tool tip. Otherwise, the dense regula r low frequency vibration ripples will be scraped on the machined surface. When the tool tip is set higher than the rotating center of the work piece by three t imes of the amplitude of ultrasonic vibration, the vibration ripples behave alig ht; they turn light and shade alternatively when the tool tip is lower than the rotating center of the work piece by three times of the amplitude of ultrasonic vibration. According to the test result analyzing, the following conclusions are put forward: 1) The surface roughness in ultrasonic cutting is better than that in common cutting. Under a one third critical cutting velocity, the value of th e surface roughness in ultrasonic cutting rise slightly along with the cutting v elocity, while in common cutting it decreases contrast to the cutting velocity; the curves of the surface roughness in ultrasonic cutting and common cutting see m to be alike, both increase along with the feed rate and the cutting depth, but the value in ultrasonic cutting is smaller in the same condition.2) The influen ce of the coolant on the surface roughness cannot be ignored. The kerosene can b e employed to improve the surface roughness in ultrasonic machining.3) In ultras onic cutting process of aluminum alloy ultra-thin wall work piece, the PCD tool performs better than the cemented carbide tools.4) The vibration ripples result from the not enough rigidity of the acoustic system and the improper setting he ight of the tool tip. The departure of the tool tip from the rotating center of the work piece to some extent causes the vibration ripples on the machined surfa ce.

Ultra-Thin Body SOI MOSFET交流特性分析和结构优化

针对沟道长度为 5 0nm的UTBSOI器件进行了交流模拟工作 ,利用器件主要的性能参数 ,详细分析了UTB结构的交流特性 .通过分析UTBSOI器件的硅膜厚度、侧墙宽度等结构参数对器件交流特性的影响 ,对器件结构进行了优化 .最终针对UTBSOIMOSFET结构提出了一种缓解速度和功耗特性优化之间矛盾的方法 ,从而实现了结构参数的优化选取 。

Large energy-loss straggling of swift heavy ions in ultra-thin active silicon layers

Monte Carlo simulations reveal considerable straggling of energy loss by the same ions with the same energy in fully-depleted silicon-on-insulator （FDSOI） devices with ultra-thin sensitive silicon layers down to 2.5 rim. The absolute straggling of deposited energy decreases with decreasing thickness of the active silicon layer. While the relative straggling increases gradually with decreasing thickness of silicon films and exhibits a sharp rise as the thickness of the silicon film descends below a threshold value of 50 nm, with the dispersion of deposited energy ascending above ~10%. Ion species and energy dependence of the energy-loss straggling are also investigated. For a given beam, the dispersion of deposited energy results in large uncertainty on the actual linear energy transfer （LET） of incident ions, and thus single event effect （SEE） responses, which pose great challenges for traditional error rate prediction methods.

Research on Influence of Cutting Conditions on Roundness of Ultra-thin Wall Parts in Ultrasonic Vibration Cutting

In the paper, the experimental researches were carr ie d out to discuss the roundness forming rule and the influence of cutting paramet ers on roundness by ultrasonic vibration cutting of the camera’s guiding drawtu be with 47.75 mm diameter and 0.6～1.5 mm wall thickness. The research results s h ow that the roundness error of ultra-thin wall parts in ultrasonic vibration cu tting is only one third of that in common cutting. The relations between the rou ndness error and the cutting parameters behave as: (1) The roundness error in co mmon cutting decreases gradually with the rise of cutting speed, while in ultras onic cutting, the roundness changes not obviously till the cutting speed is up t o a value, which is nearly equal to one third of the critical velocity. Then the roundness of workpiece will begin to increase slowly. (2) The roundness error i ncreases along with the feed rate both in common cutting and ultrasonic cutting. (3) Within the range of cutting depth in experiment, the influence of cutting d epth on the roundness error is more obvious in common cutting than that in ultra sonic vibration cutting. The conclusions are useful in machining such precise ul tra-thin wall parts. According to the tests, the following conclusions can be o btained: 1) Compared with common cutting, ultrasonic cutting can decrease effect ively roundness error of the workpiece. Under the same condition, the roundness error of the ultra-thin wall part in ultrasonic turning is about one third of t hat in common cutting. 2) In common cutting, cutting depth and feed rate have mu ch influence on the roundness and the influence of cutting velocity is little. W hile in ultrasonic cutting, the roundness was influenced heavily only when feed rate is more than 0.1 mm/r and cutting speed is more than 1/3 of the critical ro tation speed, cutting depth has little influence on the roundness in the experim ent. 3) Kerosene-oil is an optimum cutting fluid in machining ultra-thin wall workpiece. 4) To machine the ultra-thin wall precision part, ultrasonic cutting is the perfect method which can decrease the roundness error effectively an d ensure high quality of the surface.

Ultra-thin circularly polarized lens antenna based on single-layered transparent metasurface

Circularly polarized （CP） lens antenna has been applied to numerous wireless communication systems based on its unique advantages such as high antenna gain, low manufacturing cost, especially stable data transmission between the transmitter and the receiver. Unfortunately, current available CP lens antennas mostly suffer from high profile, low aperture efficiency as well as complex design. In this paper, we propose an ultra-thin CP lens antenna based on the designed single- layered Pancharatnam-Berry （PB） transparent metasurface with focusing property. The PB metasurface exhibits a high transmissivity, which ensures a high efficiency of the focusing property. Launched the metasurface with a CP patch antenna at its focal point, a low-profile lens antenna is simulated and measured. The experimental results show that our lens antenna exhibits a series of advantages including high radiation gain of 20.7 dB, aperture efficiency better than 41.3%, and also narrow half power beam width （HPBW） of 13°at about 14GHz. Our finding opens a door to realize ultra-thin transparent metasurface with other functionalities or at other working frequencies.

New process for production of ultra-thin grain oriented silicon steel

The Hi-B silicon steels were cold rolled by cross shear rolling (CSR) with different mismatch speed ratio(MSR)s and conventional rolling(CR) respectively, followed by primary recrystallization annealing. The effects of MSR and annealing temperature on magnetic properties of ultra-thin grain oriented silicon steel were analyzed. Experimental results show that, with the increase of MSR, the magnetic properties can be remarkably improved. The higher the annealing temperature is, the higher the magnetic induction and the lower the iron loss in ultra-thin silicon steel is.

The conduction mechanism of stress induced leakage current through ultra-thin gate oxide under constant voltage stresses

The conduction mechanism of stress induced leakage current （SILC） through 2nm gate oxide is studied over a gate voltage range between 1.7V and stress voltage under constant voltage stress （CVS）. The simulation results show that the SILC is formed by trap-assisted tunnelling （TAT） process which is dominated by oxide traps induced by high field stresses. Their energy levels obtained by this work are approximately 1.9eV from the oxide conduction band, and the traps are believed to be the oxygen-related donor-like defects induced by high field stresses. The dependence of the trap density on stress time and oxide electric field is also investigated.

Development of a High-PerformanceFlexible Substrate for Flexible Electronics:Joining TAC Films and an Ultra-Thin Glassby Using TEOS-DAC Synthesized by the Sol-Gel Method

A new flexible substrate for flexible electronics has been developed. The developed substrate consists of an ultra thin glass and TAC (triacethyl cellulose) film. An ultra thin glass and TAC film were joined with TEOS-DAC (TEOS: tetraethyl orthosilicate, DAC: diacethy cellulose) adhesive resin synthesized by sol-gel method by means of thermo-compression bonding. This substrate has high transparency in visible-light region (90%), high flexibility (torsion strength and bending strength) and high gas barrier characteristics due to an ultra thin glass. The newly-developed substrate is superior to the substrates fabricated with commercially available adhesive resin in the same way in characteristics of heat resistance, transparency and flexibility.