硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境
Summary
我们对在HF原位改变处理的Si（001）面成亲水或疏水状态通过照射在微流体室中填充用H 2 O 2 / H 2 O的溶液（0.01％-0.5％）或甲醇溶液样品的处理报告使用相对低的脉冲能量密度的脉冲UV激光。
Abstract
硅的可润湿性（Si）为在该材料的生物传感装置的制造和表面官能化的技术的重要参数之一。我们报告使用的KrF或ArF激光照射沉浸在与脉冲数低的液体环境中的Si（001）样品，并运行在适度低脉冲能量密度诱导硅润湿性修改的协议。晶圆浸泡长达4小时的0.01％H 2 O 2 / H 2 O解决方案并没有表现出他们的初始接触角（CA）〜75°可衡量的变化。然而，这样的晶片在一个微室500脉冲的KrF或ArF激光照射填充有0.01％ 的 H 2 O 2 / H 2 O的溶液，在250和65毫焦耳/厘米2，分别下降CA以接近15°，表示超亲水表面的形成。 OH-为端的Si（001），形成与晶片的表面形貌的任何可测量的变化，具有已证实通过X射线光电子能谱法和原子力显微镜测量。选择性区域照射样品然后浸入生物素缀合的荧光素染色的纳米球的溶液2小时，从而在非照射区域中的纳米球的一个成功的固定。这说明该方法用于选择性区域biofunctionalization和先进的基于Si的生物传感结构制造的潜力。我们还描述了使用ArF激光器晶片浸渍在甲醇（CH 3 OH）的照射的类似协议在65毫焦耳的脉冲能量密度运行/厘米2和就地形成的Si（001）的强疏水性表面具有103在CA度。该XPS结果表明ArF激光器诱导形成Si-所示的（OCH 3）λ化合物负责观察到的疏水性。但是，没有这样的化合物被发现通过XPS在Si表面上由KrF激光器在甲醇照射，展示出的KrF激光器的无能photodissociate甲醇和创建-OCH 3基团。
Introduction
显着的电子和化学性能以及它的高机械强度作出硅（Si）为微电子器件和生物医学芯片1的理想选择。在Si表面的选择区域控制已收到显著关注涉及微流体和实验室片上的设备2,3。这通常是获得或者由表面粗糙度的纳米级修饰或通过在表面4的化学处理的应用程序。的表面粗糙化或图案化，以产生在Si表面上无序或有序的表面结构包括光刻法5，离子束光刻6和激光技术7。与这些方法相比，激光表面纹理化工艺被报道是较不复杂的带，以产生微结构以高空间分辨率8的潜力。然而，由于Si具有升高的纹理阈值，要求照射脉冲能量密度，以导致表面纹理超过了其烧蚀阈值（〜500毫焦耳/ 平方厘米）9，硅表面的纹理经常被协助通过采用活性气体环境，如高压六氟化硫环境4,7,8的。因此，要修改的Si表面的润湿性，许多工作已通过沉积有机10和无机膜2，或使用等离子体或电子束的表面处理11,12集中在化学处理。人们认识Si的亲水性从单数和关联的OH基团在其表面上的存在始发可以通过煮沸它在100℃的H 2 O的2溶液数分钟13来实现。然而，所述疏水硅表面状态，其中大部分是由于的Si-H或Si-O-CH 3基团的存在，可以通过湿法化学处理包括用HF酸溶液或涂布有光致抗蚀剂13的蚀刻来实现-15。为了实现硅的润湿性的选择区域的控制，通常需要复杂的构图步骤，其中包括处理化学溶液16。的紫外激光辐射的高化学反应性也被用来选择性区域处理有机膜涂覆固体基材和修改他们的润湿性17。然而，有限的数据量可在Si润湿性通过浸渍在不同的化学溶液的样品照射激光辅助修改。
在我们以前的研究中，第III-V族半导体中的空气18-20和NH 3 21紫外激光照射被成功用于改变砷化镓，砷化铟镓和InP的表面化学组成。我们建立了第III-V族半导体，紫外线激光照射在去离子（DI）水减少表面氧化物和碳化物，而吸附在半导体表面上的水增加了22。一个强疏水性的硅表面（CA〜103°），通过硅样品的ArF激光器照射获得在甲醇中的最近的工作23。如图中箭头X射线光电子能谱（XPS），这主要是由于在ArF激光器的至photodissociate CH 3 OH的能力。我们也使用的KrF或ArF激光照射的Si（001） 在 H 2 O 2在去离子水中的0.01％。这使我们能够实现选择性区域形成的Si超亲水表面（001）的特征在于邻近15°的CA。该XPS结果表明，这是由于产生的的Si-OH键上的照射表面24。
这种新技术的使用的KrF或ArF激光选择性区 Si表面的亲水/疏水表面原位改性的H 2 O 2 / H 2 O和甲醇溶液浓度低的详细说明证明这篇文章。这里提供的细节应该足够让类似的实验，由感兴趣的研究人员进行。
Protocol
Representative Results
Discussion
我们提出的Si晶片的紫外激光照射的协议中的微流体腔室填充有H 2 O 2的溶液低浓度以诱导超亲水Si表面，这主要是由于的Si-OH的生成。的H 2 O 2的紫外激光光解被认为以形成负电荷的OH –基团。另外，紫外激光光电效应导致带正电的表面37的形成。因此，这些负OH的相互作用–自由基与带正电的表面导致的Si-OH的生成的表面上。所以，我们可以增?…
Divulgazioni
The authors have nothing to disclose.
Acknowledgements
This work was supported by the Natural Science and Engineering Research Council of Canada (Discovery Grant No. 122795-2010) and the program of the Canada Research Chair in Quantum Semiconductors (JJD). The help provided by Xiaohuan Xuang, Mohamed Walid Hassen and technical assistance of Sonia Blais of the Université de Sherbrooke Centre de caractérisation de matériaux (CCM) in collecting XPS data are greatly appreciated. NL acknowledges the Merit Scholarship Program for Foreign Student, Fonds de recherche du Québec – Nature et technologies, for providing a graduate student scholarship.
Materials
| fluorescein stained nanospheres | Invitrogen | F8795 | |
| OptiClear | National Diagnostics | OE-101 | |
| ArF laser (λ=193 nm) | Lumonics | pulse master 800 | |
| KrF laser (λ=248 nm) | Lumonics | pulse master 800 | |
| XPS | Kratos Analytical | AXIS Ultra DLD | |
| Fluorescence microscope | Olympus | IX71 | |
| XPS quantitification software | CasaXPS | 2.3.15 |
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