Vertical assembly of carbon nanotubes for via interconnects

The via interconnects are key components in ultra-large scale integrated circuits(ULSI).This paper deals with a new method to create single-walled carbon nanotubes(SWNTs) via interconnects using alternating dielectrophoresis(DEP).Carbon nanotubes are vertically assembled in the microscale via-holes successfully at room temperature under ambient condition.The electrical evaluation of the SWNT vias reveals that our DEP assembly technique is highly reliable and the success rate of assembly can be as high as 90%.We also propose and test possible approaches to reducing the contact resistance between CNT vias and metal electrodes.     

Al_(66)Mn_9Ti_(25) La金属间化合物的变形行为与机制

研究了微量稀土元素La对Al6 6 Mn9Ti2 5 金属间化合物显微组织、变形行为、裂纹生成的影响。在Al6 6 Mn9Ti2 5 金属间化合物中添加微量La ,保持L12 结构 ,晶格常数基本无变化 ,促进了晶粒枝晶化和第二相弥散化 ,起到一定的抑制微裂纹生成和扩展以及沿晶开裂的作用 ;同时 ,还可增强位错的可动性 ,使压缩塑性得到改善。探讨了La改善变形行为的机制。     

α-Fe_2O_3纳米线和体材料的拉曼光谱的温度依赖性

研究了α-Fe2O3体材料和纳米线的拉曼光谱的频率对温度的依赖性,认为纯温度效应是影响其拉曼光谱温度依赖性的主要因素。讨论了α-Fe2O3纳米线和体材料的拉曼光谱温度依赖性不同的根源。     

Enhanced etching of silicon didioxide guided by carbon nanotubes in HF solution

This paper describes a new method to create nanoscale SiO₂ pits or channels using single-walled carbon nanotubes (SWNTs) in an HF solution at room temperature within a few seconds. Using aligned SWNT arrays, a pattern of nanoscale SiO₂ channels can be prepared. The nanoscale SiO₂ patterns can also be created on the surface of three-dimensional (3D) SiO₂ substrate and even the nanoscale trenches can be constructed with arbitrary shapes. A possible mechanism for this enhanced etching of SiO₂ has been qualitatively analysed using defects in SWNTs, combined with H₃O⁺ electric double layers around SWNTs in an HF solution.     

Al66Mn9Ti25＋La金属间化合物的变形行为与机制

研究了微量稀土元素L对Al66Mn9Ti25 La金属间化合物显微组织、变形行为、裂纹生成的影响。在Al66Mn9Ti25 La金属间化合物中添加微量La,保持L12结构，晶格常数基本无变化，促进了晶粒枝晶化和第二相弥散化，起到一定的抑制微裂纹生成和扩展以及沿晶开裂的作用；同时，还可增强位错的可动性，使压缩塑性得到改善，探讨了La改善变形行为的机制。     

用纯铁氧化法生长的铁氧化物样品的拉曼光谱研究

用显微拉曼光谱对纯铁氧化法生长的新铁氧化物材料进行了结构鉴认和成分分析。实验和分析清楚地证明样品的顶层长出了纳米结构的α—Fe2O3,中间层的主要成分是Fe3O4,底层在测量时很可能是与α—Fe2O3相近的成分。     

Radio-frequency transistors from millimeter-scale graphene domains

Graphene is a new promising candidate for application in radio-frequency(RF) electronics due to its excellent electronic properties such as ultrahigh carrier mobility, large threshold current density, and high saturation velocity. Recently,much progress has been made in the graphene-based RF field-effect transistors(RF-FETs). Here we present for the first time the high-performance top-gated RF transistors using millimeter-scale single graphene domain on a SiO2/Si substrate through a conventional microfabrication process. A maximum cut-off frequency of 178 GHz and a peak maximum oscillation frequency of 35 GHz are achieved in the graphene-domain-based FET with a gate length of 50 nm and 150 nm,respectively. This work shows that the millimeter-scale single graphene domain has great potential applications in RF devices and circuits.