Nanofabrication

K. H. Brown, Proc. Soc. Photo-Opt. Instr. Eng. 2438, 33 (1995). A good source of information on the new exposure technologies can be found in the Proceedings of the International Conference on Electron, Ion and Photon Beam Technology and Nanofabrication, pubhshed annuaUy in Issue 6 of the Journal of Vacuum Science and Technology B. 

The most recent approach to reductive nanofabrication that can indeed constmct nanoscale stmctures and devices uses microscopic tools (local probes) that can build the stmctures atom by atom, or molecule by molecule. Optical methods using laser cooling (optical molasses) are also being developed to manipulate nanoscale stmctures. 

Several striking examples demonstrating the atomically precise control exercised by the STM have been reported. A "quantum corral" of Fe atoms has been fabricated by placing 48 atoms in a circle on a flat Cu(lll) surface at 4K (Fig. 4) (94). Both STM (under ultrahigh vacuum) and atomic force microscopy (AFM, under ambient conditions) have been employed to fabricate nanoscale magnetic mounds of Fe, Co, Ni, and CoCr on metal and insulator substrates (95). The AFM has also been used to deposit organic material, such as octadecanethiol onto the surface of mica (96). New appHcations of this type of nanofabrication ate being reported at an ever-faster rate (97—99). 

Table 2. Some Approaches in Reductive (Top Down) and Synthetic (Bottom Up) Nanofabrication...

Filling CNTs represents a remarkable example of manipulation of matter at the nanometric level. The experiments described here clearly show example of the capacities and potentialities for nanofabrication of novel materials. 

Luo K, Shi Z, Varesi J, Majumdar A (1997) Sensor nanofabrication, performance, and conduction mechanisms in scanning thermal microscopy. J Vac Sci Technol B 15 349-360 Majumdar A (1999) Scanning thermal microscopy. Annu Rev Mater Sci 29 505-585 Manghk RM, Wasekar VM, Zhang J (2001) Dynamic and equilibrium surface tension of aqueous surfactant and polymeric solutions. Exp Thermal Fluid Sd 25 55-64... 

The fabrication of such a system can be accomplished only by nanofabrication, and different routes can be imagined in this context. We will focus in the following section on the template-controlled growth of metal clusters on thin oxide films, which has proven to give excellent results in terms of low complexity. This approach has been successfully employed for metal-on-metal systems (for a comprehensive review see [6]) and has recently been extended to metal growth on oxide films. 

Ruiz-Hitzky, E., Aranda, P. and Darder, M. (2007) in Bottom-Up Nanofabrication Supramolecules, Self-Assemblies, and Organized Films (eds. Ariga, K. and Nalwa, H.S.) American Scientific Publishers 9,... 

Lvov, Y., Price, R., Gaber, B. and Ichinose, I. (2002) Thin film nanofabrication via layer-by-layer adsorption of tubule halloysite, spherical silica, proteins and polycations. Colloids and Surfaces Engineering, 198-200, 375-382. 

Recent progress in nanofabrication has shown that SW-CNTs have become an essential building block for nanoelectromechanical systems (NEMSs) and... 

Clark, P., in Nanofabrication and Biosystems Integrating Materials Science, Engineering and Biology (H. C. Hoch, L. W. Jelinski, and H. G. Craighead, Eds.), p. 357. Cambridge University Press, Cambridge, UK (1996). 

Electroless deposition as we know it today has had many applications, e.g., in corrosion prevention [5-8], and electronics [9]. Although it yields a limited number of metals and alloys compared to electrodeposition, materials with unique properties, such as Ni-P (corrosion resistance) and Co-P (magnetic properties), are readily obtained by electroless deposition. It is in principle easier to obtain coatings of uniform thickness and composition using the electroless process, since one does not have the current density uniformity problem of electrodeposition. However, as we shall see, the practitioner of electroless deposition needs to be aware of the actions of solution additives and dissolved O2 gas on deposition kinetics, which affect deposit thickness and composition uniformity. Nevertheless, electroless deposition is experiencing increased interest in microelectronics, in part due to the need to replace expensive vacuum metallization methods with less expensive and selective deposition methods. The need to find creative deposition methods in the emerging field of nanofabrication is generating much interest in electroless deposition, at the present time more so as a useful process however, than as a subject of serious research. 

Cui Z (2008) Nanofabrication principles, capabilities and limits. Springer, Heidelberg... 

Fig. 2 (a) Schematic representation of a mechanically controlled break junction (MCBJ). The inset shows the SEM image of a nanofabricated gold bridge [40]. (b) Principle of an STM-based break junction experiment (STM-BJ)... 

Inoue, S., Tsuda, H., Tanaka, T., Kobayashi, M., Magoshi, Y., and Magoshi, J. (2003). Nanostructure of natural fibrous protein In vitro nanofabric formation of Sarnia cynthia ricini wild silk fibroin by self-assembling. Nano Lett. 3, 1329-1332. 

Surface roughness was measured according to ANSI standard 1346.1-(1978) using a Tencor Instruments Alpha-Step 200 stylus profilometer located at the National Nanofabrication Facility of Cornell. Five surface roughness measurements were made for each sample and their average values recorded. Details of the experimental apparatus set-up and its operation are given elsewhere (Dems, B. C. et. al. Inti. Polvm. Proc.. in press.). 

This work was supported by the Office of Naval Research. This work was performed in part at the National Nanofabrication Facility at Cornell University which is partially supported by the National Science Foundation. 

Kumar C.S.S.R., Hormes, J., and Leuschner, C., Eds., Nanofabrication Towards Biomedical Applications, Wiley, Weinheim, 2005. 

Fig. 8 Schematic of nanofabrication methodology (left) and SEM image of Co nanowire array (right). Reproduced from [29]... 

Fig. 13 Nanofabrication process for obtaining spatially controlled nanopores. Reproduced from [52]...

---