关于纳米技术的应用现状及展望

关于纳米技术的应用现状及展望【论文关键词】：纳米科学纳米技术纳米管【论文摘要】：讨论纳米科学和技术在新时期里发展所面对的困难和挑战。

一系列新的方法将被讨论。

我们还将讨论倘若这些困难能够被克服我们可能会有的收获。

纳米科学和技术所涉及的是具有尺寸在1-100纳米范围的结构的制备和表征。

在这个领域的研究举世瞩目。

无论是从基础研究（探索基于非经典效应的新物理现象）的观念出发，还是从应用（受因结构减少空间维度而带来的优点以及因应半导体器件特征尺寸持续减小而需要这两个方面的因素驱使）的角度来看，纳米结构都是令人极其感兴趣的。

1. 纳米结构的制备有两种制备纳米结构的基本方法：build-up和 build-down。

所谓build-up方法就是将已预制好的纳米部件（纳米团簇、纳米线以及纳米管）组装起来；而build-down 方法就是将纳米结构直接地淀积在衬底上。

前一种方法包含有三个基本步骤：1）纳米部件的制备；2）纳米部件的整理和筛选；3）纳米部件组装成器件（这可以包括不同的步骤如固定在衬底及电接触的淀积等等）；“Build-down”方法提供了杰出的材料纯度控制，而且它的制造机理与现代工业装置相匹配，换句话说，它是利用广泛已知的各种外延技术如分子束外延(MBE)、化学气相淀积（MOVCD）等来进行器件制造的传统方法。

“Build-down”方法的缺点是较高的成本。

很清楚纳米科学的首次浪潮发生在过去的十年中。

在这段时期，研究者已经证明了纳米结构的许多崭新的性质。

学者们更进一步征明可以用“build-down”或者“build-up” 方法来进行纳米结构制造。

这些成果向我们展示，如果纳米结构能够大量且廉价地被制造出来，我们必将收获更多的成果。

2. 纳米结构尺寸、成份、位序以及密度的控制为了充分发挥量子点的优势之处，我们必须能够控制量子点的位置、大小、成份已及密度。

其中一个可行的方法是将量子点生长在已经预刻有图形的衬底上。

由于量子点的横向尺寸要处在10-20纳米范围（或者更小才能避免高激发态子能级效应，如对于GaN材料量子点的横向尺寸要小于8纳米）才能实现室温工作的光电子器件，在衬底上刻蚀如此小的图形是一项挑战性的技术难题。

对于单电子晶体管来说，如果它们能在室温下工作，则要求量子点的直径要小至1-5纳米的范围。

这些微小尺度要求已超过了传统光刻所能达到的精度极限。

有几项技术可望用于如此的衬底图形制作。

⑴ 电子束光刻通常可以用来制作特征尺度小至50纳米的图形。

如果特殊薄膜能够用作衬底来最小化电子散射问题，那特征尺寸小至2纳米的图形可以制作出来。

⑵ 聚焦离子束光刻是一种机制上类似于电子束光刻的技术。

⑶ 扫描微探针术可以用来划刻或者氧化衬底表面，甚至可以用来操纵单个原子和分子。

最常用的方法是基于材料在探针作用下引入的高度局域化增强的氧化机制的。

⑷ 多孔膜作为淀积掩版的技术。

多孔膜能用多种光刻术再加腐蚀来制备，它也可以用简单的阳极氧化方法来制备。

⑸ 倍塞（diblock）共聚物图形制作术是一种基于不同聚合物的混合物能够产生可控及可重复的相分离机制的技术。

⑹ 与倍塞共聚物图形制作术紧密相关的一项技术是纳米球珠光刻术。

此项技术的基本思路是将在旋转涂敷的球珠膜中形成的图形转移到衬底上。

⑺ 将图形从母体版转移到衬底上的其他光刻技术。

几种所谓“软光刻“方法，比如复制铸模法、微接触印刷法、溶剂辅助铸模法以及用硬模版浮雕法等已被探索开发。

3. 纳米制造所面对的困难和挑战随着器件持续微型化的趋势的发展，普通光刻技术的精度将很快达到它的由光的衍射定律以及材料物理性质所确定的基本物理极限。

通过采用深紫外光和相移版，以及修正光学近邻干扰效应等措施，特征尺寸小至80 nm的图形已能用普通光刻技术制备出。

然而不大可能用普通光刻技术再进一步显著缩小尺寸。

采用X光和EUV 的光刻技术仍在研发之中，可是发展这些技术遇到在光刻胶以及模版制备上的诸多困难。

目前来看，虽然也有一些具挑战性的问题需要解决，特别是需要克服电子束散射以及相关联的近邻干扰效应问题，但投影式电子束光刻似乎是有希望的一种技术。

扫描微探针技术提供了能分辨单个原子或分子的无可匹敌的精度，可是此项技术却有固有的慢速度，目前还不清楚通过给它加装阵列悬臂樑能否使它达到可以接受的刻写速度。

对一个理想的纳米刻写技术而言，它的运行和维修成本应该低，它应具备可靠地制备尺寸小但密度高的纳米结构的能力，还应有在非平面上刻制图形的能力以及制备三维结构的功能。

此外，它也应能够做高速并行操作，而且引入的缺陷密度要低。

然而时至今日，仍然没有任何一项能制作亚100 nm图形的单项技术能同时满足上述所有条件。

现在还难说是否上述技术中的一种或者它们的某种组合会取代传统的光刻技术。

究竟是现有刻写技术的组合还是一种全新的技术会成为最终的纳米刻写技术还有待于观察。

4. 展望目前，已有不少纳米尺度图形刻制技术，它们仅有的短处要么是刻写速度慢要么是刻写复杂图形的能力有限。

这些技术可以用来制造简单的纳米原型器件，这将能使我们研究这些器件的性质以及探讨优化器件结构以便进一步地改善它们的性能。

必须发展新的表征技术，这不单是为了器件表征，也是为了能使我们拥有一个对器件制造过程中的必要工艺如版对准的能进行监控的手段。

随着器件尺度的持续缩小，对制造技术的要求会更苛刻，理所当然地对评判方法的要求也变得更严格。

随着光学有源区尺寸的缩小，崭新的光学现象很有可能被发现，这可能导致发明新的光电子器件。

然而，不象电子工业发展那样需要寻找MOS晶体管的替代品，光电子工业并没有如此的立时尖锐问题需要迫切解决。

纳米探测器和纳米传感器是一个全新的领域，目前还难以预测它的进一步发展趋势。

然而，基于对崭新诊断技术的预期需要，我们有理由相信这将是一个快速发展的领域。

总括起来，在所有三个主要领域里应用纳米结构所要求的共同点是对纳米结构的尺寸、材料纯度、位序以及成份的精确控制。

一旦这个问题能够解决，就会有大量的崭新器件诞生和被研究。

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Either from basic research (based on non-classical effects explore new physical phenomena) concept, or from the application (by reducing the dimension of space due to structural advantages brought about as a result of the semiconductor device feature sizes continue to be reduced and need these two aspects factors driven) perspective, nano structures are very great interest.1.NanostructuresThere are two basic methods of preparation of nanostructures : build-up and build-down. Theso-called build-up method is to have preformed nm member ( nanoclusters , nanowires and nanotubes ) assembled ; the build-down method is to nanostructures directly deposited on the substrate . The former method is composed of three basic steps: 1 ) Preparation of nanometer member ; 2 ) nano- finishing and screening member ; 3 ) nano- components into the device( which can include different steps , such as fixed electric contact of the substrate and deposition plot , etc. ); "Build-down" approach provides excellent control of material purity , and its mechanism of modern industrial equipment manufacturing match , in other words , it is the most widely known use of the various epitaxial techniques such as molecular beam epitaxy (MBE), chemical vapor deposition (MOVCD) like the conventional method for device fabrication . "Build-down" approach is that higher costs.Nanoscience is clear first wave occurred in the past decade . During this period, researchers have proven many new nanostructured nature . Zheng Ming scholars can further "build-down" or "build-up" approach to nanostructure fabrication . These results show us that if a large number of nano-structures can be produced at low cost , we will certainly gain more results.2.Nanostructure size , composition , rank , and density controlIn order to give full play the advantages of quantum dots of the Department, we must be able to control the quantum dot location, size , composition and density have been . One possible approach is to grow in quantum dots has been pre- engraved pattern on the substrate . Because the lateral quantum dot size to the nanometer range in 10-20 ( or smaller in order to avoid highly excited states sublevels effects, such as quantum dots for GaN materials lateral dimensions less than 8 nm ) can be achieved optoelectronic devices operating at room temperature , etched on the substrate so that a small graphical challenging technical problems. For the single-electron transistor , if they can work at room temperature , the diameter of the quantum dots is required to be small in the range 1-5 nm . These tiny scale requires more than the traditional lithographic limits the achievable accuracy . Several techniques could be used for such a substrate graphicsproduction .⑴electron beam lithography can often be used to make features as small as 50 nanometers scale graphics. If special film can be used as a substrate to minimize electron scattering problem, that feature sizes as small as 2 nm graphics can be produced .⑵focused ion beam lithography is a mechanism similar to electron beam lithography technology.⑶scanning microprobe technique can be used to scribe or oxidation of the substrate surface and can even be used to manipulate individual atoms and molecules. The most common method is based on material under the action of the probe into the highly localized enhanced oxidation mechanism .⑷version porous membrane as a deposition mask technology. A variety of porous film can be prepared by photolithography plus etching , it can be used simply prepared by anodic oxidation method .⑸X plug (diblock) copolymers graphic production technique is based on a mixture of different polymers to produce controlled and reproducible technique of phase separation mechanism .⑹and double stuffed copolymer graphics production technique is closely related to a technology nanospheres pearl engraved surgery . The basic idea of this technique is to rotate the coated beads in the formed film pattern transfer onto the substrate.⑺the graphic version transferred from the mother to the substrate other lithography. Severalso-called "soft lithography " approach , such as copying casting method, micro-contact printing method, solvent-assisted molding method and embossed with a hard template method has been developed to explore .3 .nanometer manufacturing difficulties and challenges faced byContinuing miniaturization of devices along with the trend of development, the general accuracy of lithography will soon reach its laws by the diffraction of light and physical properties of materials are determined by fundamental physical limits. By using deep UV and phase shift version, and amendments to the optical interference effect neighbors and other measures, feature sizes as small as 80 nm graphics have been able to prepare ordinary lithography . However unlikely an ordinary lithography further significantly reduced in size . Using X-ray and EUV lithography technology is still being developed , but the development of these technologies and the photoresist stencil encountered many difficulties on the preparation . At present , although there are some challenging problems to be solved , in particular the need to overcome the electron beam scattering and interference effects associated with the neighbor , but the projection electron beam lithography seems to be a promising technique . Scanning microprobe technique provides can distinguish individual atoms or molecules unmatched precision , but there are inherent in the technology slow speed , it is unclear cantilever array by giving it to install it can achieve an acceptable the carved speed.Carved on an ideal nano technology, its operation and maintenance costs should be low, it should be prepared with reliable high density small in size but the capacity nanostructures, there should be non-plane patterning capabilities and Preparation function of three-dimensional structure. Furthermore, it should also be able to operate in parallel for high-speed, and lower density of defects introduced. Today, however, still no one can produce a single sub-100 nm graphics technology can satisfy all the conditions above. Now the above technique is difficult to saywhether one or a combination of them will replace a conventional photolithographic techniques. What is the combination of existing technologies or carved a new technology will become the ultimate nano-carved technology remains to be seen.4 Looking At presentThere are many graphic nanoscale lithography techniques , their only weaknesses are either slow either carved carved complex graphics capabilities are limited. These techniques can be used to make a simple prototype device nm , which will enable us to study and explore the nature of these devices in order to optimize the device structure to further improve their performance. New characterization techniques must be developed , not only for device characterization , but also to enable us to have a manufacturing process of the device as a necessary process can be monitored aligned version means. As devices continue to shrink scale of manufacturing technology requirements will be more demanding , of course, on the evaluation method requirements are becoming more stringent . With the reduced size of the optical active region , a new optical phenomena are likely to be found , which may lead to the invention of new optoelectronic devices . However , unlike the electronics industry as the need to find alternatives to the MOS transistors , optoelectronics industry is not so acute problem needs to be urgently addressed immediately . Nm detector and nano sensor is a new field, it is still difficult to predict the further development trend . However, based on the anticipated needs of new diagnostic techniques , we have reason to believe this will be a rapidly developing field . In sum , in all three main areas of application ofnano-structures required in common is the size of nano- structure , material purity , rank and composition of precise control. Once this problem can be solved , there will be a lot of new birth and the device being studied .References[1] Wang Miao, Li Zhenhua, Lu Yang, Qi Zhongfu, Li cast Nanomaterials Applied Technology Progress [J]. Materials Science and Engineering, 2000.[2] Wu Jing. Electrospray ionization method step preparation containing bonded phase nanospheres study [D]. Tianjin University, 2006.[3] Zhang Ximei, Chen Ling, Li Lin, Guo Siyuan nano materials research Status and Development direction [J]. modern Chemical Industry, 2000.[4] Zhu Xueqin nanotechnology and Its Application [J]. new technology & New Process, 1996.[5] Zhangchen Li nanotube equivalent elastic buckling behavior parameters and molecular dynamics simulation [D]. Shanghai Jiaotong University, 2007.。