硅／多孔硅异质结光生电压谱研究

首次报道硅／多孔硅异质结光生电压谱，发现多孔硅的激发能有不连续性，表明多孔硅量子点由一层层硅原子有序排列而构成，其尺寸分布是不连续的，其差值为硅晶格常数的整数倍，光生电压谱是研究多孔硅和硅／多孔硅异质结能带结构的有效方法．     

深硅槽开挖工艺

本文介绍了硅槽应用,即硅槽隔离和硅槽电容,对器件性能的改善。并介绍了硅槽隔离和硅槽电容的形成步骤及硅槽刻蚀剖面的形貌控制,CBrF_3刻蚀硅槽侧壁保护层的形成等等。     

具有初生硅相的亚共晶铝硅合金的微观组织

无论是亚共晶或共晶铝硅合金中针状共晶硅还是过共晶铝硅合金中的粗大块状初生硅都严重割裂了基体，降低了铝硅合金的强韧性。为此，铝硅合金通常要变质处理来改善硅相的形态，使过共晶铝硅合金中的初生硅相和共晶硅相或共晶与亚共晶铝硅合金中的共晶硅相细化成粒状或短棒...     

硅／多孔硅异结光生电压谱研究

首次报道硅／多孔硅异质结光生电压谱，发现多孔硅的激发能有不连续性，表明多孔硅量子点由一层层硅硅原子有序排列而构成，其尺寸分布是不连续的，其差值为硅晶格常数的整数倍，光生电压谱是研究多孔硅和硅／多孔硅异质结能带结构的有效方法。     

硅发光研究与进展

微电子技术的瓶颈和信息技术发展的需求加速了光电子学在硅基材料上实现光信息处理、光电子集成的研究,利用硅基材料制造出高质量的发光器件对光电子学以至整个信息技术均具有重要意义.由于受间接带隙能带结构的限制,天然硅材料具有很低的发光效率,不利于硅光源的实现.通过采用人工改性的方法提高硅的发光效率,多孔硅、硅纳米晶体、掺Er3+硅纳米晶和硅的受激拉曼散射均是目前可实现硅发光甚至硅激光的可行途径.回顾硅发光研究的历史进程,归纳总结了近年来可实现硅发光几种方法的原理、特点以及当前的研究进展.相信随着硅发光效率的提高及器件制备工艺的发展,硅发光研究不久将出现重大突破性成果,并有可能引起新的信息技术革命.     

硅纳米颗粒和多孔硅的荧光光谱研究

采用不同氧化电流密度制备多孔硅,利用超声波粉碎多孔硅层得到硅纳米颗粒,研究了多孔硅和硅纳米颗粒的荧光光谱性质。结果表明,随着氧化电流密度的增加．多孔硅的发光峰值波长向短波方向“蓝移”。硅纳米颗粒相对多孔硅发光强度提高,峰值波长也发生“蓝移”,观察到硅纳米颗粒极强的蓝紫光发射(≈400nm)现象。表明量子限制效应和表面态对多孔硅和硅纳米颗粒的PL性质有重要作用,并用量子限制效应发光中心模型对实验现象进行了解释。     

一维多孔硅光子晶体的三阶非线性光学性质

在工艺参数实验和理论设计分析的基础上,制备 了包括多孔硅Bragg反射镜、多孔硅微腔和稳定 性很好的多孔硅三元结构在内的多孔硅一维光子晶体,对3种多孔硅光子晶体的结构进行了 表征,不同孔 隙度的多孔硅呈现出周期性的排列。采用单光束反射Z扫描方法 分别对3种结构的多孔硅在1064nm波长处的 非线性折射率进行了测量。实验结果表明,多孔硅三元结构光子晶体的三阶非线性折射率比 多孔硅Bragg 反射镜和多孔硅微腔高1个数量级,这将为多孔硅一维光子晶体用于先进光电器件的设计提 供了重要参考。     

C60/硅基介孔复合物的发光研究

用化学沉积法制备了C60/多孔硅以及C60/硅基多孔氧化铝两种硅基介孔复合物,并研究了它们的发光性质.结果表明C60的毗联可以影响多孔硅的发光性质,但对硅基多孔氧化铝的发光基本不产生影响.这种现象可以从多孔硅以及硅基多孔氧化铝的发光机理进行解释.     

用于硅衬底隔离的选择性多孔硅厚膜的制备

在硅衬底上形成高阻隔离层对于提高硅基射频电路的性能具有重要意义。采用多孔硅厚膜作为隔离层 ,能够极大地降低衬底高频损耗。本文对n+型硅衬底上选择性多孔硅厚膜的制备进行了研究。通过在阳极氧化反应中采用不同的HF溶液的浓度、电流密度和反应时间来控制多孔硅的膜厚、孔隙度等特性。有效地减少了多孔硅的龟裂失效 ,得到的多孔硅最大膜厚为 72 μm。并测量了多孔硅的生长速率与表面形貌     

硅基太赫兹技术及未来趋势

不同于传统的太赫兹组件,基于硅基的太赫兹系统在大规模使用情况下具有成本低,尺寸小,集成度高,操作性强,更容易实现大阵列等特点。近10年来,随着硅基半导体技术的快速发展和硅基工艺晶体管的截止频率提升,硅基太赫兹系统芯片的设计发展迅猛。本文将主要从硅基太赫兹源、硅基太赫兹成像芯片、硅基太赫兹通信芯片、硅基太赫兹雷达芯片四个方面对当前的硅基太赫兹系统芯片的研究现状和发展趋势进行综述。     

硅纳米线的电学特性

总结了硅纳米线在电学特性方面的研究进展,重点分析了本征及掺杂硅纳米线的载流子浓度与迁移率、场发射及电子输运特性。研究表明通过对硅纳米线进行掺杂可提高载流子浓度及迁移率、场发射和电子输运性能,随硅纳米线直径的减小其电学性能增强。因此,硅纳米线在场效应晶体管及存储元件等纳米器件方面具有极大的应用前景。     

Field emission of vertically-aligned carbon nanotube arrays grown on porous silicon substrate

Vertically aligned arrays of multi-walled carbon nanotubes were grown by pyrolysis of acetylene on iron catalytic particles within a porous silicon template via chemical vapor deposition (CVD) at 700 °C. Using this method ordered nanotubes with diameters from 75 to 100 nm could be produced. The diode configuration field emission of the CNT arrays were performed and the onset electric field is 4 V/μm and the emission current can approach 1 mA/cm² at a electric field of 9.5 V/μm. The enhancement factor of the CNT arrays (4012) is derived from the F–N plot of the experiment data. To demonstrate the uniformity of the field emission, an ITO glass substrate with phosphor coated is used as anode in the field emission experiment. The average fluctuation of the emission current density was less than 5%. The result shows that the field emission of the CNT arrays on the silicon substrate is very uniform. These carbon nanotube arrays are useful for applications in field emission displays and sensors. The fabrication method shows the feasibility of integration between carbon nanotube arrays and silicon microelectronics.     

多孔硅场致电子发射

研究了多孔硅冷阴极的场致电子发射特性，实验表明采用电化学阳极腐蚀、氧化、蒸电极等工艺可以制备一种平面薄膜型多孔硅冷阴极。在超高真空环境下测量了多孔硅冷阴极的电子发射特性。     

阳极氧化条件对多孔硅冷阴极场发射特性的影响

研究了多孔硅的制备条件对多孔硅冷阴极场发射特性的影响,实验表明多孔硅的制备条件如电解电流密度、电解时间等多孔硅冷阴极的场发射特性有较大的影响。     

Fabrication and enhanced field emission properties of novel silicon nanostructures

We reported the fabrication and the field emission properties of two-tier novel silicon nanostructures. First, silicon nanopillars with ordered high aspect ratio were achieved by using conventional lithographic techniques to act as the field emission sources. Second, sharp-edged well-aligned silicon nanograss was fabricated on top of the nanopillars by means of hydrogen plasma dry etching to induce the field emission characteristics. The turn-on fields were obtained as 10.5 and 14.4 V/μm under current density of 0.01 mA/cm² for two-tier patterns separated by respective 5 μm and 2 μm spaces. The excellent field emission property from these novel nanostructures exhibited a great potential as high-performance field emitter arrays towards future nanoelectronic devices.     

纳米多孔硅的场致电子发射性能研究

对采用阳极氧化法及阴极还原表面处理技术制备的性能稳定的纳米多孔硅,用原子力显微镜(AFM)表征了其微观结构,多孔硅颗粒粒径在30 nm左右.室温条件下测试了多孔硅场电子发射的特性,结果表明,多孔硅具有很好的场致发光性能,在5 V/μm的电场下就可以产生场发射电流.多孔硅的开启电压在1 000 V左右,发射电流随着电压的增大而不断增大,发射电压在2 000 V以上.

Abstract：

Nanoscale porous silicon (PS) was prepared by anodic oxidation, cathode reduction and surface treatment technique. The porous silicon particles with the average diameter of about 30 nm were obtained by characterizing their microstructure with atomic force microscope (AFM). Electron field emission characteristics of porous silicon were investigated at room temperature. The resuhs demonstrate that porous silicon has favorable electroluminescence properties, and the field emission current can be generated only under the electric field of 5 V/ μm. And the turn - on voltage is about 1 000 V. With the increase of the offered voltage, the emission current is enhanced and the emission voltage is over 2 000 V.     

Field Emission Properties of Nanostructured Silicon Cathode Arrays

The fabrication method of field electron sources using the atomic structure of silicon crystals and the processes of heterophase vacuum-plasma self-organization of island carbon coatings and highly anisotropic plasma-chemical etching under low adsorption is theoretically justified and experimentally implemented. The interrelation of the morphological and field emission characteristics of fabricated field emission cathodic microstructures is established. The experimental results are interpreted using the Fowler-Nordheim representation in connection with the changes of the surface phases of multipoint silicon microstructures.     

Structure and electrical characteristics of silicon field emissionmicroelectronic devices

Field emission current was measured from arrays of wet chemically etched silicon cold-cathode diodes. Two types of cathode tips were measured both as-etched and after sharpening by low-temperature oxidation. The field enhancement increase resulting from tip sharpening is less than expected from simulation. The currents measured follow a Fowler-Nordheim characteristic and are temperature insensitive from 130 to 360 K. Turn-on voltage is near 4 V, a value much less than measured from most other field emission sources. With a 920-nm anode-cathode spacing, a minimum 0.2-μA current per cathode was found. Telegraph noise of about 1% at 20 V was observed. These sharpened silicon tips are a viable cold cathode for vacuum microelectronics and other electron device applications     

ZnO纳米棒的图形化生长及其场发射特性

介绍了用氢离子注入技术和阳极腐蚀方法在硼掺杂p-(100)型硅晶片上制备图形化的纳米硅(SiNC)薄膜工艺，并在这种图形化衬底上成功生长了图形化的ZnO纳米棒. 场发射测试表明制备的ZnO纳米棒具有良好的场发射性能，即具有较低的开启电场和阈值电场，较高的发射点密度.     

Silicide application on gated single-crystal, polycrystalline andamorphous silicon FEAs. I. Mo silicide

In order to improve both the level and the stability of electron field emission, the tip surface of silicon field emitters have been coated with a molybdenum layer of thickness 25 nm through the gate opening and annealed rapidly at 1000°C in inert gas ambient. The gate voltages of single-crystal silicon (c-Si), polycrystalline silicon (poly-Si) and amorphous silicon (a-Si) field emitter arrays (FEAs) required to obtain anode current of 10 nA per tip are 90 V, 69 V, and 84 V, respectively. In the case of the silicide emitters based on c-Si, poly-Si and a-Si, these gate voltages are 76 V, 63 V, and 69 V, respectively. Compared with c-Si, poly Si and a-Si field emitters, the application of Mo silicide on the same silicon field emitters exhibited 9.6 times, 2.1 times, and 4.2 times higher maximum emission current, and 6.1 times, 3.7 times, and 3.1 times lower current fluctuation, respectively. Moreover, the emission currents of the silicide FEAs depending on vacuum level are almost same in the range of 10^-9~10^-6 torr. This result shows that silicide is robust in terms of anode current degradation due to the absorption of air molecules