Molecular-scale engineering for future electronics

Summary form only given. As the push continues to attain smaller devices and increasing circuit density, the use of individual molecules as device and circuit components becomes progressively more attractive. Molecules are highly uniform and inherently nanoscale, which could be very advantageous for the fabrication of ultra-dense, low-power ICs. Furthermore, they can be synthesized with unique chemical, physical and biological properties that could be used to facilitate self-assembly to one another and to specific surfaces, and to form elements that can perform information processing. The "bottom- up" concept of "molecular electronics" represents a paradigm shift, in which the naturally small starting components self-assemble into devices and circuits. This inherent simplicity may offer significant economic advantage over the traditional "top-down" semiconductor-based approach. Thus, research in molecular electronics has generated considerable interest in recent years. While the concept of molecular electronics is not new and a wide variety, of molecules have been considered as candidates, the last few years have witnessed significant research advances. Custom-synthesized molecules have exhibited useful electronic functions such as switching and memory. Carbon nanotubes, with a diameter as small as 1 nm, have shown transistor-like properties. Meanwhile, others have used the molecular recognition properties of DNA to facilitate the self-assembly of nanoscale structures. Some of these advances will be described. However, while these molecules provide unique features, each has its own individual technical challenges too. And interfacing with the micro-/macro-worlds will also be a key issue. So, while molecular electronics hold tremendous promise as an alternate to conventional scaling, much more interdisciplinary research still remain in order to realize its full potential