ELECTRONIC DEVICES Nanowire transistors made easy

摘要

In all modern transistors, the flow of current is modulated by a gate electrode, which alters the charge density in a thin region at the surface of a channel (Fig. l a), This modulation almost always relies on junctions between the channel and source and drain contacts, which have different doping types or densities. These junctions are becoming increasingly difficult to manufacture as transistor sizes are reduced in the pursuit of performance. However, the first field-effect transistor (FET) to be patented (by Julius Edgar Lilienfeld in 1925) did not use any junctions whatsoever'. Lilienfeld's "device for controlling the electric current" was effectivelya resistor (or more exactly, a three-terminal resistivity-modulated semiconductor) that could be depleted of charge carriers by the action of a gate. To turn the device completely off by fully depleting its body of carriers, however, required a very thin nanoscale channel for which the technology did not exist at the time.