NER: Direct Electron Beam Writing for Fabrication of Functional Nano-Scale Architectures

该提案是根据NSE， NSF-0019收到的。聚焦电子束分解吸附在表面的分子将被研究作为制造单个或小纳米结构阵列的电接触的一种手段。这种直接写入技术为弥合介观光刻和纳米级光刻之间的差距提供了一种方便、灵活和实用的方法。最重要的是沉积膜的纯度和电阻率。电阻率将通过沉积在预先定义的金属接触垫之间与工艺参数相关联。使用TaF5、TiCl4和WF6等无机前驱体分子可避免沉积金属特征的污染。薄膜纯度将使用标准表面科学技术在现场测定。环境电子显微镜中可实现的写入速度的初步估计表明，1:1的纵横比，纳米尺度的电线可以以0.1 μ m /秒的速率写入。此外，使用环境电子显微镜将允许同时识别和接触感兴趣的特征。这种技术的灵活性将允许为不同的应用定制沉积结构。例如，用于电接触的纳米线，用于连接功能化有机分子的金属纳米点阵列，或沉积在半导体表面的特殊形状的金属门，以允许在纳米尺度区域内进行电荷限制和操作。因此，这项技术的成功将使跨越几个纳米科学和技术子领域的各种概念的快速原型化成为可能。从长远来看，电子束写入整个纳米器件的能力是被设想的。电子束分解导致半导体和绝缘体生长的无机物质也将被研究。新的前体化学物质将被开发用于电子束生长与硅基纳米电子学兼容的绝缘和半导体相。从本质上讲，这是一种非热方法，用于在低于沉积原子表面扩散的温度下沉积纳米级特征。

This proposal was recieved in response to NSE, NSF-0019. Focused electron beam decomposition of molecules adsorbed on surfaces will be investigated as a means for fabricating electrical contacts to individual or small arrays of nanostructures. This direct write technique offers a convenient, flexible and practical method for bridging the gap between mesoscopic lithography and the nanoscale. Of primary importance is the purity and resistivity of the deposited film. Resistivity will be correlated with process parameters by depositing between predefined metallic contact pads. Contamination of deposited metallic features will be avoided by using inorganic precursor molecules such as TaF5, TiCl4 and WF6 . Film purity will be determined in situ ,using standard surface science techniques. Preliminary estimates of write speeds achievable in environmental electron microscopes indicate that 1:1 aspect ratio,nm-scale wires can be written at rates of 0.1 um /sec. Additionally, use of environmental electron microscopy will allow simultaneous identification and contacting features of interest. The flexibility of this technique will allow tailoring the deposited structures for different applications. Examples are nanowires for electrical contacts, metal nanodot arrays for attachment of functionalized organic molecules or specially shaped metal gates deposited on semiconductor surfaces to allow charge confinement and manipulation in nanoscale regions. Thus,success of this technique will enable rapid prototyping of diverse concepts cutting across several nanoscience and technology subfields. Longer term, the capability for e-beam writing of entire nanodevices is envisioned. Electron-beam decomposition of inorganic species leading to growth of semiconductors and insulators will also be investigated. Novel precursor chemistries will be developed for e-beam growth of insulating and semiconducting phases compatible with Si-based nanoelectronics. Essentially,this is an athermal method for depositing nanoscale features at temperatures below that for which the features 'melt' via surface diffusion of deposited atoms.