Nanoelectronics

The developments in integrated circuits and storage devices used in computers have proceeded at an exponential rate: at present it takes two to three years for each successive halving of the component size. Information storage has followed a similar trend in miniaturization of the size of the bits of magnetized material used in hard disks. However, these current technologies have fundamental limits, below which the devices no longer function in a predictable manner. For instance, the thin oxide layers used in complimentary metal oxide semiconductor (CMOS) devices are becoming so thin that they conduct electricity in a quantum-mechanic manner by electron tunneling. In 1998, it was estimated that microelectronics and magnetic storage technologies would reach their ultimate limits within 10 to 30 years. Abstractions for very-large-scale integration (VLSI) predict that a single chip will accommodate 90 million transistors with a feature size of 70 nm and a clock speed of 900 MHz by the year 2010. Current microelectronic technology has been responsible for the evolution of electronics from the millimeter to the micrometer scale. Currently, many critical dimensions in semiconductor devices are in the 100-nanometer range, with some insulating layers being tens of nanometers thick. Industry is keen to drive miniaturization even further.