Breakthrough in Single-Electron Device Fabrication

Laptop computers that are lighter and generate less heat. Portable memory devices the size of a thumbnail or a quarter that can store the equivalent of hundreds of movies. These are some of the possible results of a new technology - single-electron devices - that will allow integrated circuit chip manufacturers to go beyond existing limits of size and operating efficiency by packing huge numbers of circuits in a small space.

Single-electron devices have many advantages over conventional electronic devices; they can have ultra-high packing density and operate with extremely low power consumption. Researchers have been working on these devices for more than a decade; however, various fabrication challenges have limited their production to only a small number of devices at a time, restricting their practical implementation. In developmental breakthroughs, Materials Science & Engineering researchers at The University of Texas at Arlington have created new single-electron device designs and processes that enable their fabrication on a large scale.

Assistant Professor Seong Jin Koh and his four doctoral students, collaborating with Professor Choong-Un Kim, have overcome several roadblocks to attain three major achievements: The devices can be fabricated using current integrated circuit fabrication processes and equipment; they can be assembled in a completely parallel manner, producing multiple numbers of devices at a time.

Until now, the fabrication of single-electron devices had been carried out using sophisticated, most often individualized, nanoscale techniques that have limitations for large-area parallel production. The self-aligned, nanoscale devices created by Koh and his team have a vertical structure, with thin dielectric films separating the source and drain electrodes, that can be fabricated using existing CMOS assembly methods and materials.

Many early examples of single-electron devices had to be cooled to very low temperatures, most often below -250o C, to function, making them impractical for widespread use. The ability to operate at room temperature brings these new devices into the realm of practical and widespread applications.

These unique features can make Koh and his team’s devices the foundation of the next generation of data storage devices. These achievements are the result of a $400,000, five-year Faculty Early Career Development (CAREER) research grant Koh received from National Science Foundation in 2005. The Office of Naval Research and Texas Higher Education Coordinating Board also supported the research.

All claims in a patent application have been allowed and Koh expects a patent to be granted later this year.

A complete description of their study may be seen in the October 2008 issue of Nature Nanotechnology - http://www.nature.com/nnano/journal/v3/n10/abs/nnano.2008.267.html