Donev Eugenii U, Hastings J Todd
Department of Electrical and Computer Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
Nano Lett. 2009 Jul;9(7):2715-8. doi: 10.1021/nl9012216.
We demonstrate here the first focused electron-beam-induced deposition (EBID) of nanostructures using a liquid precursor. We have deposited sub-50 nm platinum (Pt) wires and dots from a dilute, aqueous solution of chloroplatinic acid. Existing EBID processes rely on the electron-beam stimulated decomposition of gaseous precursors; as a result, the deposits are highly contaminated (up to 75 at. % carbon or 60 at. % phosphorus for Pt processes). In contrast, we show that deposition of platinum by electron-beam reduction of platinum ions from solution leads to high-purity deposits (approximately 10 at. % chlorine contamination) at rates at least ten times higher than those obtained with other platinum precursors. Liquid-phase EBID offers a new route to deterministic, three-dimensional, nanometer-scale structures composed of multiple materials without complex multistep processing. Thus, it may prove important for prototyping and low-volume production of nanoscale devices and for repair and modification of nanoscale masks and templates used in high-volume production.
我们在此展示了首次使用液体前驱体进行的聚焦电子束诱导沉积（EBID）制备纳米结构。我们已从氯铂酸的稀水溶液中沉积出了直径小于50纳米的铂（Pt）线和点。现有的EBID工艺依赖于电子束刺激气态前驱体的分解；因此，沉积物受到高度污染（对于铂工艺，碳含量高达75原子%或磷含量高达60原子%）。相比之下，我们表明通过电子束还原溶液中的铂离子来沉积铂，能够以至少比使用其他铂前驱体高十倍的速率获得高纯度沉积物（氯污染约为10原子%）。液相EBID为无需复杂多步工艺即可制备由多种材料组成的确定性三维纳米级结构提供了一条新途径。因此，它对于纳米级器件的原型制作和小批量生产，以及对于大批量生产中使用的纳米级掩膜和模板的修复与改性可能具有重要意义。
