Electrical Properties of Compositional Al2O3 Supplemented HfO2 Thin Films by Atomic Layer Deposition

With advanced research for dielectrics including capacitors in DRAMs, decoupling filters in microcircuits and insulating gates in transistors, a lot of demand for the new challenging of high-k materials in semiconductor industries has been emerged. This study explores and addresses the experimental approach for composite materials with one of the major concerns of high capacitance, and low leakage, as well as ease of integration technology. The characteristics of Al2O3 supported HfO2 (AHO) thin films for a series of different Hf ratios with Al2O3 dielectrics by atomic layer deposition demonstrated as a candidate material. A composite AHO films with the homogeneous compositions of Al and Hf atoms into the Al-Hf-O mixed oxide system could stabilize the polycrystalline structure with increasing of dielectric constant (k) and decreasing of leakage current density, as well as a higher breakdown voltage than HfO2 film on its own. 70 nm thick AHO thin films with different composition of Al and Hf contents were prepared by atomic layer deposition technique on titanium nitride (TiN) and silicon dioxide (SiO2) coated Si substrates. Photolithography and metal lift-off technique were used for the device fabrication of the metal-insulator-metal (MIM) capacitor structures. AHO films on TiN/SiO2/Si were measured by semiconductor analyzer and source/ measure system with probe station in the voltage range from -5 to 5 V with a frequency range from 10 kHz to 1 MHz were used to conduct capacitance-voltage (C-V) measurements with low/medium frequency range and current-voltage (I-V) measurements. It was found that Au/AHO/TiN/SiO2/Si MIM capacitors demonstrate a capacitance density of 1.5 - 4.5 fF/μm2 at 10 kHz, a loss tangent of 0.02 - 0.04 at 10 kHz, dielectric constant of 11.7 - 35.5 depending on the composition and a low leakage current of 1.7 × 10-9 A/cm2 at 0.5 MV/cm at room temperature. The acquired experimental results could show the possibility of compositional alloy thin films that could potentially replace or open new market for high-k challenges in semiconductor technology.

Composition change and capacitance properties of ruthenium oxide thin film

Ru O2·n H2O film was deposited on tantalum foils by electrodeposition and heat treatment using Ru Cl3·3H2O as precursor.Surface morphology, composition change and cyclic voltammetry from precursor to amorphous and crystalline RuO2·n H2O films were studied by X-ray diffractometer, Fourier transformation infrared spectrometer, differential thermal analyzer, scanning electron microscope and electrochemical analyzer, respectively. The results show that the precursor was transformed gradually from amorphous to crystalline phase with temperature. When heat treated at 300 °C for 2h, RuO2·n H2O electrode surface gains mass of2.5 mg/cm2 with specific capacitance of 782 F/g. Besides, it is found that the specific capacitance of the film decreased by roughly20% with voltage scan rate increasing from 5 to 250 m V/s.

Chlorine Gas Sensors with HPS Film on Interdigitated Capacitors

The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were performed at room temperature for frequencies 100 Hz,1 kHz and 10 kHz.It is shown that there is a linear relationship between the capacitance and the concentration of chlorine gas.Influences of the measurement frequency and film thickness of silicate on the sensitivity of the sensor to C12 gas were discussed.And organically modified N,N-diethylaminopropyl-trimethoxysilane (APMS) had a much higher sensitivity.

薄膜电容器数据挖掘与分析

作为电力系统的重要元件之一,薄膜电容器因长使用寿命、高可靠性等优点而受到广泛应用,然而却极少有研究从数据角度挖掘电容器的自身属性。为了填补这一空白,本文选取收集自网络的40793条薄膜电容器数据作为分析基础,首先利用散点图和箱线图从横向角度分析了不同材料制备而成的电容器的容值、最高最低温度、交直流运行电压等差异,然后利用饼图从纵向角度对比了电容器的运行温度和应用场合,最后计算出这些性能指标的皮尔逊系数并进行了相关性分析。结果表明金属化聚丙烯材料作为目前的主流材料在容值和交直流运行电压方面比其他材料均具有显著的优势,而金属化聚苯硫醚在运行温度上占优,电容器除温度和运行电压外的各项参数之间的相关性并不显著。未来可以进一步对数据进行处理和学习,达到性能预测的效果。

储能电容无机电介质薄膜研究进展

无机电介质薄膜相对有机电介质材料具有更高的工作温度范围,相对无机块体陶瓷材料又有更高的击穿场强和储能密度,因而近年来受到研究者的关注.从无机电介质薄膜材料的5种类型:顺电薄膜、铁电薄膜、弛豫铁电薄膜、反铁电薄膜和线性电介质薄膜,分类综述了过去10余年这个领域优化其储能性能的手段与思路,从不同尺度归纳无机电介质薄膜的储能改性策略,最后展望发展趋势,如应用场景的挖掘、能量效率与能量密度的平衡和多尺度改性等.

HFO_(2)铁电体薄膜移相器设计

移相器作为阵列天线的关键部件,用来调整阵列天线中各个天线单元之间的相位差,从而实现波束的扫描。基于传输线周期性加载可变电容理论,设计了一款工作于K波段的HFO_(2)铁电薄膜移相器。为了实现低插损和紧凑型,该移相器采用HFO_(2)铁电体薄膜材料,相比传统的BST材料,其有着更大的调谐率、厚度更薄且损耗角正切更低,容易集成,同时结合共面波导叉指电容结构设计,该移相器有非常紧凑的尺寸。通过改变HFO_(2)铁电材料的介电常数从而实现电容的变化,进而实现相位的调控。仿真结果表明,通过加入直流偏置电压改变铁电体薄膜的介电常数,该移相器在22 GHz频点的移相量为80°,最大插损为-2.5 dB,回波损耗优于-10 dB。

Experimental Characterization of ALD Grown Al<SUB>2</SUB>O<SUB>3</SUB>Film for Microelectronic Applications

The study of high dielectric materials has received great attention lately as a key passive component for the application of metal-insulator-metal (MIM) capacitors. In this paper, 50 nm thick Al2O3 thin films have been prepared by atomic layer deposition technique on indium tin oxide (ITO) pre-coated glass substrates and titanium nitride (TiN) coated Si substrates with typical MIM capacitor structure. Photolithography and metal lift-off technique were used for processing of the MIM capacitors. Semiconductor Analyzer with probe station was used to perform capacitance-voltage (C-V) characterization with low-medium frequency range. Current-voltage (I-V) characteristics of MIM capacitors were measured on precision source/measurement system. The performance of Al2O3 films of MIM capacitors on glass was examined in the voltage range from −5 to 5 V with a frequency range from 10 kHz to 5 MHz. Au/Al2O3/ITO/Glass MIM capacitors demonstrate a capacitance density of 1.6 fF/μm2at 100 kHz, a loss tangent ~0.005 at 100 kHz and a leakage current of 1.79 × 10−8 A/cm2 at 1 MV/cm (5 V) at room temperature. Au/Al2O3/TiN/Si MIM capacitors demonstrate a capacitance density of 1.5 fF/μm2 at 100 kHz, a loss tangent ~0.007 at 100 kHz and a lower leakage current of 2.93 × 10−10 A/cm2 at 1 MV/cm (5 V) at room temperature. The obtained electrical properties could indicate a promising application of MIM Capacitors.

电压继电器指示灯闪烁现象的失效机理分析

电压继电器作为电力系统中常用的保护器件得到了广泛的应用。根据组件失效分析的方法步骤对电压继电器现场出现的报警灯闪烁失效的原因进行了分析,结合继电器的电路和测试结果,采用无损分析和破坏性分析,定位到了失效的薄膜电容器。再进一步对失效的薄膜电容器进行分析,确定了薄膜电容器内部电极箔腐蚀氧化,造成容量下降,从而引起VCC电源电压波动,最终导致电压继电器报警灯闪烁。建议高湿环境下,电压继电器需采用更好的封装,避免薄膜电容氧化腐蚀。

Al_(2)O_(3)层厚度对PbZrO_(3)/Al_(2)O_(3)异质结薄膜储能性能的影响

为了提高Pt/PbZrO_(3)/Pt电介质电容器的储能密度,通过热蒸镀和自然氧化方法在Pt/Ti/SiO_(2)/Si基板上沉积了厚度为0~10 nm的Al_(2)O_(3)(AO)层,采用化学溶液沉积法制备PbZrO_(3)薄膜,研究了Al_(2)O_(3)层厚度对PbZrO_(3)/Al_(2)O_(3)(PZO/AO)异质结薄膜储能性能的影响。结果表明:随着AO层厚度的增加,PZO/AO异质结薄膜的击穿电场强度逐渐增大,极化电场电滞回线由反铁电特征转变为铁电特征。当PZO/AO异质结薄膜的AO层厚度为5 nm时,储能密度最大值为21.2 J/cm^(3)。

Fabrication Process of Sol-Gel Spin Coating for SrBi2Ta2O9 Films Applied to FeRAM

We investigate SrBi2 Ta2 O9 （SBT） films prepared by the sol-gel spin method with different spin rates or different anneal conditions for the first layer of SBT, as promising ferroelectric layer materials applied to ferroelectric random access memory （FeRAM）. All the specimens in this experiment have similar SBT crystal orientations of （115）, （020）, （220）, and （135）. The Pt/SBT/Pt capacitor with coating of 3000rpm spin rate has a perfect rectangle shape of hysteresis loops, remanent polarization of 7.571μC/cm^2 and coercive voltage of 0.816 V at 5 V voltage amplitude. These characteristics are better than those with coating of 3500rpm spin rate, which is attributed to the influence for thickness and grain size of the film from depressed spin rate. Slow-rate anneal in the furnace for the first layer of SBT can improve the crystallization processes and properties for SBT layers slightly, compared with rapid thermal annealing. The ion damage from etching for the top electrode can influence leakage current characteristics of the Pt/SBT/Pt capacitor at positive voltage bias.

(1-x)PbZrO_(3)-xBaTiO_(3)薄膜的制备及储能性能

电介质电容器在脉冲功率领域具有广阔的应用前景,其储能密度和储能效率的提高是目前研究的热点。通过PbZrO_(3)(PZO)和BaTiO_(3)(BTO)两相固溶的方式,制备(1-x)PZO-xBTO(x为0、0.1、0.2、0.3和0.4)固溶体薄膜,旨在提高介电强度,从而改善其储能密度和储能效率。结果表明:随着BTO含量增加,薄膜的晶粒尺寸逐渐减小,且薄膜由反铁电体逐渐转变为弛豫铁电体,导致其介电强度提高。当x=0.3时,(1-x)PZO-xBTO薄膜具有最大的可恢复储能密度,为11.62 J/cm^(3),较纯PZO薄膜提高了31.6%。当x=0.4时,薄膜储能效率达到62.3%,较纯PZO薄膜提高了62.7%。

薄膜电容器的研究与设计

为了有效解决薄膜电容器生产中薄膜尺寸和卷制圈数的问题,本文主要研究了多串膜结构薄膜电容器的理论设计,采用原理分析和公式推导方法从平行板电容工作原理到多串膜结构薄膜尺寸和卷制圈数设计,最后通过全自动卷绕机和电容测试仪验证电容量和卷制圈数关系式,实现对卷制生产活动的有效指导和多串膜电容的合理设计。

电解电容与薄膜电容的对比分析

在综合现有文献基础上,对电解电容与薄膜电容的优缺点进行了对比分析。首先,分析了影响铝电解电容寿命的主要因素,给出了对电解电容寿命进行估算的方法。然后,针对交-直-交电力电子变换器,在综合考虑电容容值、电流有效值、过电压、负载功率等多因素的情况下,对直流支撑电容进行了设计,说明了在功率变化电路中薄膜电容远优于电解电容。最后,针对两类大型电力电容器,分别采用电解电容方案与薄膜电容方案进行了对比设计。结果表明:与电解电容方案相比,薄膜电容方案不仅具有寿命长、耐压高、电流承受能力强、能承受反压、无酸污染并且可长时间存贮等诸多优点,而且在体积上也明显小于电解电容方案。

层层自组装技术的研究进展及应用情况

层层自组装技术(Layer-by-layer self-assembly,LbL)是正处于发展阶段的新技术。与传统成膜技术相比,该技术能组装的材料多种多样(如聚电解质、纳米颗粒、有机小分子等),可以通过模板精确控制薄膜的表面结构和尺寸。薄膜的通透性能和力学性能可以通过控制组装材料、沉积层数、组装条件等来改善。对层层自组装技术的研究进展及应用情况进行了综述,较为详细地介绍了层与层之间作用力的研究进展,阐述了LbL技术在电化学电容器、光敏微胶囊、分离膜、生物化学及药物释放中的应用。

基于叉指结构的平面分形电容研究

以基于叉指结构的平面分形电容为研究对象,电容由激光刻蚀法制得,在测得其S参数后,利用ADS仿真工具进行了一阶等效电路参数提取及分析.结果表明,随着共面叉指电极间距的相对减小,电极间的耦合增大,相应的寄生电感也增大;而分形设计可以在保证电极间距不变的情况下,改善电容的工作稳定性.最后制得的分形平面电容的电容值在1~7 pF之间,电容稳定工作频率可达2.5 GHz以上,显示了较好的可调性和稳定性.

BST薄膜电容器的制备及其调谐性能研究

利用氩离子束溅射技术在SiO2/Si衬底上淀积Ba0.8Sr0.2TiO3(BST)薄膜,该薄膜在氧气气氛中500℃退火处理30 min,然后利用集成电路平面工艺将薄膜制作成叉指结构电容器。X-射线衍射仪(XRD)和扫描电镜(SEM)分析表明,BST薄膜具有钙钛矿结构,薄膜表面光滑,晶粒致密且分布均匀。调谐性能测试结果表明,该电容器具有较高的电容调谐率,在室温100 kHz频率下,对于2 V的直流偏压,其调谐率和损耗因子分别为62%和0.02。这说明具有此结构的BST薄膜电容器可望应用于微波集成电路。

生长温度对PLD原位生长SrTiO_3薄膜结构与非线性介电性能的影响

采用脉冲激光沉积法 ( PLD ) 制备的Y1B2Cu3O7-x薄膜作为叉指底电极,然后生长 SrTiO3介质薄膜,形成叉指型压控电容结构。通过对 SrTiO3薄膜的原位生长温度与薄膜微观结构及非线性介电性能之间的关系研究,发现随生长温度的升高薄膜晶粒逐步增大然后变小,薄膜的介电常数可调率和本征介电损耗随晶粒大小的增大而增加,而非本征损耗则随晶粒取向的增加而减小。

Au/PLT/Pt铁电薄膜电容的电学性能

用 Sol- Gel方法研制了 PL T[(Pb0 .83 L a0 .17) Ti O3 ]铁电薄膜 ,结合非挥发性铁电存储器对铁电电容的要求 ,研究了 Au/ PL T/ Pt铁电电容和漏电流、剩余极化、疲劳、开关特性和揭电常数等性能。对厚度为 0 .4 μm的薄膜 ,5 V时的剩余极化强度 Pr=2 2 μC/ cm2 ,矫顽场强度 Ec=6 0k V/ cm,相对介电常数约 130 0 ,漏电流 Id=3.2× 10 -8A/ mm2 ,开关特性优良。疲劳测试表明 ,对Vpp=10 V的锯齿信号 ,经 4 .5× 10 11周期后 ,剩余极化强度衰减 2 0 %。上述性能表明 ,该 PL

钽电容器用钽壳内壁RuO_2薄膜电极的表征及电化学性能

采用涂覆热分解氯化钌的方法,在金属钽壳内壁表面形成二氧化钌薄膜涂层,作为钽电容器的负极材料,可以提高全钽电容器的寿命及可靠性.采用扫描电子显微镜和X射线衍射仪对二氧化钌薄膜的表面形貌和结构进行表征.采用循环伏安、恒流充放电和电化学阻抗谱等测试手段来表征二氧化钌薄膜电极的电化学性能.研究结果表明,热处理温度为280℃时制备的二氧化钌薄膜呈无定形的非晶态,薄膜电极具有212F/g的电容量,电化学性能良好.组装成ST3型60V330μF全钽电容器,经过赋能、电老化后容量约为345μF,等效串联电阻小于1Ω,漏电流小于10μA.

便携式薄膜太阳能光伏野外多功能应急电源的设计

目的:介绍一种在野外临时断电或无市电可利用的紧急情况下能够正常使用的便携光伏型野外多功能应急电源。方法:将目前最先进、实际光电转换效率高、弱光性强的铜铟镓铟(CIGS)薄膜太阳能电池片镶嵌在纤维基布上,制作成柔软的"薄膜太阳能光伏布",使用时展开与控制电源箱相连对其供电;不用时折叠包装后放入电源控制箱内。整个电源以太阳能光伏输入为主,以市电、发电机或汽车发动机等为辅,经过DC/AC、DC/DC、AC/DC等各种变换和系统控制后,产生直流为混合超级电容电池充电储能,最后输出直流和交流电源。结果:经过野外测试,该电源采用多种形式输入,多种途经输出,交流稳定,负载范围大,功能多,便携可满足常规设备的使用。同时质量轻、组合简单,便于野外携行、搬运。结论:该研究设计对薄膜太阳能电池光伏在移动应急电源应用方面意义重大。