Electron lithography scanning methods

Fig. 1. The accuracy of e-beam lithography is illustrated in the scanning electron micrograph (top). The size of the features formed in the silicon oxide is 0.5 pm and the typical animal cell (a fibroblast) has a diameter of 20 pm. This kind of cell adheres actively to surfaces, forming thin filopodia which here have all attached to the micro-hillocks. Semiconductor technology is capable of manufacturing micro-electrodes, sensors, pores and electronic networks with sizes smaller than that of the cell. The lower illustration summarises the main detection and measuring methods currently in use...

The methods that are commonly used to produce semiconductors and electronic materials are now being used in catalyst preparation. As recently reported, lithography has been used to deposit metal in predetermined patterns. Deposition of small clusters using nano-scale scanning tunneling microscopic tip has also been demonstrated. 

Soft lithography is a term that now encompasses a very broad range of methods for fabrication of microstruc-tured materials. It can be repeatedly used to fabricate submicrometer-sized features, and under certain conditions it can be used to fabricate sub-100 nm structures. Although the ultimate resolution achievable is poorer than that achievable with electron beam or scanning probe lithography techniques, the simplicity and versatility of soft hthogra-phy have meant that it has had a tfansformational effect on research into molecular micro- and nanosystems. 

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