Nanolithography and Nanomanipulation

In this chapter we provide a brief review of different nanolithography and nanomanipulation techniques. We discuss mainly such techniques as templated growth, dip pen lithography, anodic oxidation and scanning probe microscope based nanomanipulation. The chapter contains an introduction to the basic techniques followed by examples of such nanostructure growth. 

To begin with it is best to place the field of nanolithography and its companion nanomanipulation in perspective. This is shown in Figure 21.2. Nanomanipulation, in principle, should also include manipulation using forces of self-assembly or other chemical forces and manipulations using optical tweezers. However, the word nanomanipulation is often used in a limited context where a SPM tip is used for manipulation of a nano-object. We stick to this definition, partly to reduce the scope of the review and partly because other manipulations are not in the area of expertise of the author. 

The field of nanolithography is intimately connected with nanomanipulation. In nanomanipulation generally a preformed nanoparticle, nanotube or a nanowire is manipulated to place it at a predetermined site. The most widely used tool for nanomanipulation is the cantilever of the AFM that provides a robotic arm to place the nano-objects in predetermined sites. A nanoparticle weakly adsorbed on a substrate can be moved by an AFM tip when it works in contact mode. This is not wanted but if the particle is selected and then moved by the AFM then it becomes a useful tool. The AFM-based manipulation turns the unwanted aspect to an advantage. For instance if one wants to place a nanowire between two electrodes an AFM cantilever can be used to image the wire and push it between the two electrodes. The advantage of the cantilever is that a predetermined force can be applied and also the same instrument can image it. The basic idea behind SPM-based nanomanipulation is shown in Figure 21.17. 

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