Moore's Law, the 1965 prediction by Intel co-founder Gordon Moore that manufacturers would double the number of transistors on a chip every 18 months, has been fulfilled for four decades by the semiconductor industry. But the latest edition of the annual International Technology Roadmap for Semiconductors—a joint effort of semiconductor industry associations in Europe, Japan, Korea, Taiwan, and the United States—lists reasons for thinking that this may soon change. The Roadmap explores “technology nodes”—advances needed to keep shrinking the so-called DRAM half-pitch, half the spacing between cells in memory chips. Currently, the industry is moving to a DRAM half-pitch of 120 nanometers. The Roadmap forecasts that researchers must lower that figure to 35 nanometers by 2014, simply to continue doubling the number of transistors.

In various laboratories worldwide, minimum features sizes that are a factor of 10 smaller (or more) than the 120-nm node have been demonstrated. However the SIA (Semiconductor Industry Association) Roadmap projects that even though the miniaturization trend will continue for another 15 to 20 years, it is becoming increasingly difficult to continue to down-scale because of real physical limitations including size of atoms, wavelengths of radiation used for lithography, interconnect scheme. etc.

One of the potential roadblocks to continue the scaling beyond the 50-nm node is the molecular and biomolecular electronics. In this article we report on fundamental concepts and recent advances in the field of molecular electronics.