基于多孔阳极氧化铝的大气压毛细管等离子体电极放电研究北大核心CSCD

通过实验和模拟方式,对比分析了介质阻挡放电和基于多孔阳极氧化铝的毛细管等离子体电极放电。应用阳极氧化法制备的多孔阳极氧化铝(Porous anodic alumina,PAA)作为介质层进行了毛细管等离子体电极放电。研究了多孔阳极氧化铝介质层对毛细管等离子体电极放电的影响,对比分析了相同几何参量的介质阻挡放电和毛细管等离子体电极放电的放电过程。结果表明:应用多孔阳极氧化铝介质的毛细管等离子体电极放电更稳定,放电中产生的更密的微放电有助于提高放电的稳定性;多孔阳极氧化铝介质层的毛细管等离子体电极放电具有相对于介质阻挡放电高出两个数量级的电子密度和更高的电子温度。等离子体参数具有与多孔阳极氧化铝的孔分布同步的周期性,产生了等离子体射流模式,提高了放电稳定性。     

多孔型氧化铝薄膜在高密度封装中的应用及性能

利用铝阳极氧化方法对微晶玻璃基板上的多层铝膜进行选择性氧化,制备了4层布线的高密度MCM—D基板,对氧化得到的多孔型氧化铝介质膜的绝缘及介电性能进行了研究。实验结果表明：多层布线铝与氧化铝结合性好,层间和同层多孔氧化铝绝缘电阻分别达到10^9Ω和10^11Ω以上;多孔型氧化铝的相对介电常数和损耗分别为5．73和0．022（1MHz）;导带、互连通孔与绝缘层所形成的层间通孔互连结构共面性好,具有良好的电互连性能。多孔型氧化铝介质膜适用于制备高密度MCM—D基板。     

一种应用于PDP显示单元的CNT辅助电极制备方法及其性能评价

建立了一种应用于等离子显示器(PDP)显示单元的碳纳米管(CNT)辅助电极制备工艺方法,创新性提出了场发射作为PDP平板显示的辅助性应用,并对制备的CNT辅助电极样片进行了性能评价。文章通过三维轮廓和SEM微观形貌测试手段,表征工艺过程中CNT辅助电极的宏观尺度和微观形貌。通过拉曼光谱、傅里叶红外光谱、粒径分布和ZETA电位表征与其性能直接相关的体系分散性。通过对荷电盐浓度、电泳电压、电泳时间和阴阳极板间距的系统分析和优化,获得优化电泳参数。通过关键参数对比确定了前后处理工艺及其效果。对CNT辅助电极的场发射性能进行测试,初步评价其辅助性能并考察其与PDP单元制备流程的兼容性。优化工艺制备的CNT辅助电极场发射开启电压在10μA/cm2的电流密度时低至1.2 V/μm。虽然在MgO保护层制备后增大至1.6 V/μm,但仍可保证其作为PDP辅助电极的典型功能。所建立的CNT辅助电极制备方法具备与PDP显示单元制备工艺有良好兼容性。     

约瑟夫森结工艺系统

超导电子学和超导量子信息等领域的核心元器件是约瑟夫森结,这是一种超导体/介质层/超导体三层结构的非线性器件.超导量子比特常用铝/氧化铝/铝结构的结,在量子芯片上制备这种约瑟夫森结,需要在衬底不离开真空环境的条件下,实施离子束刻蚀、样品方位角可调的电子束蒸发、气氛可控氧化等工艺过程.自主研发的约瑟夫森结工艺系统是一套集成...     

Cu电极保护膜层氧化铝的原子层沉积工艺研究

介绍了硅功率器件Cu电极保护钝化膜层氧化铝的制备方法。采用热法ALD工艺和等离子增强ALD工艺在铜上沉积氧化铝薄膜,研究了不同ALD工艺、氧化剂种类、沉积温度和载气对氧化铝膜层质量及铜抗氧化保护效果的影响。结果表明：氧化剂对原子层沉积氧化铝薄膜的质量和铜电极的保护性能起着决定性作用;以臭氧(O₃)作为氧化剂,氧化铝薄膜极易脱落,与铜表面的结合力很差;以氧等离子体(O-)作为氧化剂,铜表面被氧化形成了氧化铜(CuO_x)层;而以水蒸气(H₂O)作为氧化剂,在低温100℃下,得到的Al₂O₃薄膜致密,无明显缺陷,且与铜金属层的结合力较优,对铜抗氧化保护效果良好;当沉积温度高于200℃时,原子层沉积氧化铝薄膜的缺陷明显增多;等离子增强ALD工艺中,当载气为Ar时,所得氧化铝膜厚度不均匀,铜电极发生强烈氧化。     

氧化铝纳米线的催化氧化法制备及表征

以汞为介质, 通过铝的催化氧化反应制备出氧化铝纳米线. 采用FE-SEM、TEM、EDX、XRD、IR等手段对氧化铝纳米线进行表征. 结果表明, 氧化铝纳米线直径为5~15nm, 无定型结构. 随着反应温度、铝纯度、反应气氛中的氧含量升高, 氧化铝纳米线比表面积增大; HgCl₂溶液浓度、铝浸入溶液的时间对氧化铝纳米线的比表面积没有明显影响.     

氧化铝膜对铝诱导制备多晶硅薄膜的影响

为了考察硅铝界面氧化铝膜对铝诱导多晶硅的影响,本文用磁控溅射方法制备了界面有无氧化铝膜的硅铝复合结构。XRD测试表明两种铝诱导方法均制备了具有(111)高度择优取向的多晶硅薄膜。光学显微镜和扫描电镜照片显示,有氧化铝膜时铝诱导的多晶硅薄膜有两层,下层为大晶粒(40μm-60μm)枝晶状多晶硅,拉曼谱显示其结晶质量接近单晶,而上层膜晶粒较小,结晶质量较差。无氧化铝膜时铝诱导的多晶硅薄膜只有单层结构,其晶体结构和结晶质量都与有氧化铝膜时铝诱导的上层多晶硅薄膜相似。结果表明,硅铝界面上氧化铝的存在大大提高了铝诱导多晶硅薄膜的质量,但是另一方面也限制了铝诱导多晶硅的晶化速率。     

多彩结构色氧化铝薄膜氧化机制的研究

在草酸电解液中,球形碳点电极作为阴极,铝箔作为阳极,利用一次氧化工艺成功的制备出了单一色彩和虹彩环形结构色的氧化铝薄膜.实验结果显示,球形碳点电极下制备的氧化铝薄膜厚度由薄膜中心向外呈对称性递减.当薄膜的径向厚度差在某一波长光的覆盖范围内时,薄膜呈现单一结构色,而当径向厚度差超出某一波长光的覆盖范围时,薄膜呈现虹彩环形结构色.本文详细的讨论了电极间距、氧化电压和氧化时间对薄膜结构色的影响,并从理论上分析了球形碳点电极下多孔氧化铝薄膜的氧化机制.     

荫罩式PDP扫描电极和荫罩对阳极条纹的影响

本文采用基于动力学模型的OOPIC仿真软件模拟具有不同扫描电极宽度和荫罩结构的荫罩式等离子显示器(PDP)放电单元内的放电过程,分析单元内的条纹数量、分布状态和介质层表面壁电荷分布情况,研究扫描电极宽度和荫罩结构对阳极条纹的影响。结果表明,扫描电极宽度增加,放电单元内的主放电区域增大,条纹可分布空间压缩,条纹现象减弱。大小孔荫罩结构也会使条纹现象减弱。研究发现,荫罩式PDP结构阳极条纹的分布区域与介质层表面电荷积累的范围密切相关,阳极条纹只出现在阳极表面介质层有壁电荷积累,而对应的阴极表面介质层无壁电荷积累的区域。     

高铝粉煤灰提取氧化铝及其废渣利用技术研究现状

高铝粉煤灰是制备氧化铝和氢氧化铝的良好原料,文章介绍了粉煤灰的基本情况以及对环境的危害,从高铝粉煤灰提取氧化铝以及利用提铝废渣制备硅酸盐水泥和白炭黑两个层次概述了近年来对粉煤灰再利用的现状。重点阐述了高铝粉煤灰提取氧化铝的制备工艺及其特点,两种主要提铝技术路线所产生的废渣用于制备硅酸盐水泥和白炭黑的研究现状,探讨了粉煤灰提取氧化铝无再次污染的工业应用方向。     

Discharge power dependence of structural and electrical properties of Al-doped ZnO conducting film by magnetron sputtering (for PDP)

In order to investigate the possible application of ZnO films as a transparent conducting oxide (TCO) electrode for AC PDP, ZnO:Al films were prepared by DC magnetron sputtering method. The effects of discharge power and doping concentration on the structural and electrical properties of ZnO films were mainly studied experimentally. Five-inch PDP cells using either a ZnO:Al or indium tin oxide (ITO) electrode were also fabricated separately under the same manufacturing conditions. The luminous properties of both the PDP cells were measured and compared with each other.By doping the ZnO target with 2 wt% of Al₂O₃, the film deposited at a discharge power of 40 W resulted in the minimum resistivity of 8.5 × 10⁻⁴ Ω-cm and a transmittance of 91.7%. However, a high doping concentration of 3 wt% of Al₂O₃ and excessive sputtering power over 40 W may induce high defect density and limit the growth of small grains. Although the luminance and luminous efficiency of the cell using ZnO:Al are lower than those of the cell with the ITO electrode by about 10%, these values are sufficient enough to be considered for the normal operation of AC PDP.     

银盐方式等离子显示器（PDP）用电磁波屏蔽膜的开发

等离子显示器（PDP）的基本工作原理是基于密封在特制的玻璃管中的氦、氙等惰性气体在高电压下产生等离子体，进行放电并放射紫外线激发管壁上的荧光物质发出蓝、绿、红三原色光线构成图像，而图像的颜色和亮度则由经过调制的脉冲电流控制，后者会同时产生电磁波干扰，影响周边环境，本文介绍富士公司开发的一种用传统银盐感光材料制作的电磁波屏蔽膜，可有效地消除PDP工作时产生的不良电磁波。     

介质保护膜制备参数对AC PDP放电特性的影响

以ＭｇＯ为例,对ＡＣ　ＰＤＰ中电子束蒸发介质保护膜制备的工艺参数,如成膜时基板温度、沉积速率、成膜后的热处理条件等对ＡＣＰＤＰ工作特性的影响进行了系统的研究和分析,讨论了保护膜成分、结构、形貌等对发射特性和ＡＣＰＤＰ工作特性的影响,探讨了成膜的最佳工艺,并根据在放电过程中,由离子轰击产生的 ＭｇＯ膜表面特性的变化和假设氧对 ＭｇＯ膜表面特性的作用,对观测到的放电特性对 ＡＣＰＤＰ板各种制造工艺参数的依赖性进行了解释。     

Texture and sheet resistance of Al alloy thin films on Ti and TiN thin films

Ti films prepared by ionized physical vapor deposition (I-PVD) and TiN films prepared by metalorganic chemical vapor deposition (MOCVD) were examined as the underlayers of the Al interconnect films. The crystallographic texture of the Al films and the sheet resistance of the thin-film stacks were investigated at various thicknesses of the Ti or TiN thin film. The sheet resistance of the thin-film stacks was also measured after annealing at 400 °C in an N₂ ambient. For the I-PVD Ti underlayer, the excellent texture of the Al (1 1 1) was obtained even on a 5-nm thick Ti film. However, the sheet resistance of the multilayer structure increased after the annealing due to the reaction between Al and Ti. MOCVD TiN layers between the Ti film and the Al film could suppress the Al–Ti reaction without severe degradation of the Al (1 1 1) texture. Excellent texture of the Al film was obtained with thin MOCVD TiN films below 5 nm.     

The use of nanoscaled Al mid-layer for enhancing the electrical conductivity of ZnO

A nanoscaled Al thin film was placed between two ZnO thin films to form a ZnO/Al/ZnO multilayer thin film structure. Individual Al and ZnO thin films with difference thicknesses were first prepared and characterized for the optical and electrical properties. The multilayer structure was then obtained by depositing individual layers with desired thicknesses in sequence. We show that by appropriate selections of layer thickness, the use of a nanoscaled Al mid-layer in ZnO enhances the electrical conductivity of the ZnO without scarifying its optical transmittance.     

Charge-trapping characteristics of Al2O3/Cu/Al2O3 nanolaminate structures prepared through atomic layer deposition

The nanolaminate Al2O3/Cu/Al2O3 structures were constructed on p-type Si (001) substrates using atomic layer deposition (ALD) process with the aim to fabricating nonvolatile charge-trap memories. Low temperature Cu thin layers were deposited through plasma-enhanced atomic layre depositon of Cu aminoalkoxide (Cu(dmamb)2) combined with hydrogen plasma and Al2O3 layers were prepared by thermal atomic layer deposition of trimethylaluminum (TMA) combined with H2O. Nonvolatile features were confirmed using capacitance-voltage (C-V) measurements. The copper film functions as a charge-trapping layer and the Al2O3 thin layers were employed as tunneling and control oxide layers. Line shapes and binding energies of Cu metal and the thin layer of 6 nm Cu in nanolaminate structures were observed in the X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (TEM) image. The V(FB) shift width of the Al2O3 (28 nm)/Cu (6 nm)/Al2O3 (4.2 nm)/Si laminate structure is found to be 4.75 V in voltage sweeping between -10 and +10 V, leading to the trap density of 1.68 x 10(18) cm(-3).     

Al2O3 and TiO2 atomic layer deposition on copper for water corrosion resistance

Al(2)O(3) and TiO(2) atomic layer deposition (ALD) were employed to develop an ultrathin barrier film on copper to prevent water corrosion. The strategy was to utilize Al(2)O(3) ALD as a pinhole-free barrier and to protect the Al(2)O(3) ALD using TiO(2) ALD. An initial set of experiments was performed at 177 °C to establish that Al(2)O(3) ALD could nucleate on copper and produce a high-quality Al(2)O(3) film. In situ quartz crystal microbalance (QCM) measurements verified that Al(2)O(3) ALD nucleated and grew efficiently on copper-plated quartz crystals at 177 °C using trimethylaluminum (TMA) and water as the reactants. An electroplating technique also established that the Al(2)O(3) ALD films had a low defect density. A second set of experiments was performed for ALD at 120 °C to study the ability of ALD films to prevent copper corrosion. These experiments revealed that an Al(2)O(3) ALD film alone was insufficient to prevent copper corrosion because of the dissolution of the Al(2)O(3) film in water. Subsequently, TiO(2) ALD was explored on copper at 120 °C using TiCl(4) and water as the reactants. The resulting TiO(2) films also did not prevent the water corrosion of copper. Fortunately, Al(2)O(3) films with a TiO(2) capping layer were much more resilient to dissolution in water and prevented the water corrosion of copper. Optical microscopy images revealed that TiO(2) capping layers as thin as 200 ? on Al(2)O(3) adhesion layers could prevent copper corrosion in water at 90 °C for ~80 days. In contrast, the copper corroded almost immediately in water at 90 °C for Al(2)O(3) and ZnO films by themselves on copper. Ellipsometer measurements revealed that Al(2)O(3) films with a thickness of ~200 ? and ZnO films with a thickness of ~250 ? dissolved in water at 90 °C in ~10 days. In contrast, the ellipsometer measurements confirmed that the TiO(2) capping layers with thicknesses of ~200 ? on the Al(2)O(3) adhesion layers protected the copper for ~80 days in water at 90 °C. The TiO(2) ALD coatings were also hydrophilic and facilitated H(2)O wetting to copper wire mesh substrates.     

Investigation of diffusion in the CuAl thin film system

An identification of the phases obtained as a result of diffusion in the CuAl thin film system and an investigation of the phase growth kinetics were carried out by means of electrochemical anode etching. Parabolic growth rates were found for the CuAl and CuAl₂ phases and also for layers with 19–24 at.% Al.     

卷绕式磁控溅射镀膜机张力控制系统分析与优化

为避免卷绕式磁控溅射镀膜过程中张力引起的薄膜缺陷,以及原有张力系统响应速度慢、稳定性差等不足,对张力系统进行了分析与优化。通过分析确定了影响张力的关键因素是收(放) 卷的速度和卷径变化,建立了张力系统动力学模型,采用simulink 对张力控制系统进行仿真分析,利用实验验证的方法,分别在原设备和改造后的设备上制备Al2 O3 薄膜,并对比其SEM 图像。改造后的系统可在0. 65 s 内实现薄膜张力实时调整,而原系统需要8 s。改造后的系统能够保证镀制过程中的张力恒定,膜层致密均匀、卷材层间无空隙和皱纹。     

Organic nonvolatile memory devices with charge trapping multilayer graphene film

We fabricated an array-type organic nonvolatile memory device with multilayer graphene (MLG) film embedded in polyimide (PI) layers. The memory devices showed a high ON/OFF ratio (over 10(6)) and a long retention time (over 10(4)?s). The switching of the Al/PI/MLG/PI/Al memory devices was due to the presence of the MLG film inserted into the PI layers. The double-log current-voltage characteristics could be explained by the space-charge-limited current conduction based on a charge-trap model. A conductive atomic force microscopy found that the conduction paths in the low-resistance ON state were distributed in a highly localized area, which was associated with a carbon-rich filamentary switching mechanism.