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

这项建议是对NSE、NSF-0019的回应。吸附在表面上的分子的聚焦电子束分解将被研究为制造与单个或小阵列纳米结构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。最重要的是沉积薄膜的纯度和电阻率。通过在预定义的金属触点焊盘之间沉积，将电阻率与工艺参数相关联。通过使用无机前体分子，如TaF5、TiCl4和WF6，将避免对沉积金属特征的污染。薄膜纯度将使用标准的表面科学技术进行现场测定。对环境电子显微镜可实现的写入速度的初步估计表明，可以以0.1微米/秒的速率写入1：1长宽比、纳米级的导线。此外，环境电子显微镜的使用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，或者沉积在半导体表面上的特殊形状的金属栅极，以允许在纳米范围内的电荷限制和操纵。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不同概念能够快速成型。从长远来看，电子束写入整个纳米设备的能力是可以预见的。电子束分解导致半导体和绝缘体生长的无机物种也将被研究。新型前驱体化学将被开发用于电子束生长与硅基纳米电子兼容的绝缘和半导体相。从本质上讲，这是一种非热沉积纳米级特征的方法，其温度低于特征通过沉积原子的表面扩散而“熔化”的温度。

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.