The Scanning Probe-Based Deep Oxidation Lithography and Its Application inStudying the Spreading of Liquid n-Alkane
The Scanning Probe-Based Deep Oxidation Lithography and Its Application inStudying the Spreading of Liquid n-Alkane
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基于扫描探针的深度氧化光刻及其在液态正烷烃扩散研究中的应用
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发表时间：
2011
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通讯作者：
Lingbo Lu
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作者：
Yuguang Cai;Lingbo Lu
我们已经开发了一种新的化学图案方法，基于扫描探针的深度氧化光刻技术，使我们能够在疏水性硅烷膜上制造羧酸端化学图案。该光刻方法采用导电原子力显微镜（AFM）探针在潮湿环境下氧化探针下的硅烷膜。当对硅烷膜施加正偏置电压时，探针下的区域被氧化为部分降解的硅烷（OTSpd），其比背景低10 a。氧化时间和AFM探针在氧化过程中的路径决定了OTSpd化学图案的大小和形状。我们可以使用OTSpd模式来控制液体正烷烃液滴在表面上的形状和大小，因为OTSpd模式是亲冻的（液体吸引）。这种新颖的化学模式方法使我们能够研究表面上的正构烷烃结构，并在分子尺度上研究液态烷烃液滴如何在模式表面上扩散。我们发现烷烃在OTSpd表面形成海藻状单层，烷烃分子可能以一定角度倾斜。进一步研究了液态烷烃液滴扩散过程中水蒸气的作用。我们发现，在液体扩散之前，烷烃液滴的蒸汽吸附在附近的表面。因此，液体实际上总是扩散在一层吸附质上。正是这种吸附质的表面性质决定了液态烷烃的扩散和润湿。
We have developed a novel chemical patterning method, the scanning probe-based deep oxidation lithography, which enables us to fabricate a carboxylic acid-terminated chemical pattern on a hydrophobic silane film. This lithography method employs a conducting atomic force microscope (AFM) probe to oxidize the silane film under the probe in a humid environment. When a positive bias voltage is applied to the silane film, the area under the probe is oxidized to the partially degraded silane (OTSpd), which is 10 A lower than the background. The oxidation time and the path of the AFM probe during the oxidation determine the size and shape of the OTSpd chemical pattern. We can use the OTSpd pattern to control shape and size of a droplet of liquid n-alkane on a surface because the OTSpd pattern is lyophilic (liquid attractive). This novel chemical pattern method enables us to study the n-alkane structures on the surface and investigates how a liquid alkane droplet spreads over patterned surfaces at molecular scale. We found that the alkane formed seaweed-shaped monolayer on the OTSpd surface, where the alkane molecules may tilt at certain angles. Furthermore, we investigated the role of vapor during the spreading of liquid alkane droplet. We found that the vapor of the alkane droplet adsorbed on the nearby surface before the liquid spread. Hence, the liquid actually always spreads on a layer of the adsorbate. It is the surface properties of this adsorbate determine the spreading and wetting of the liquid alkane.