Many researchers would be upset if their efforts began producing smaller and smaller results, but not Chia-Hung Yang, a professor of electrical engineering at the University of Maryland. That's because the product of his long hours of work are transistors that are the world's tiniest. Using a principle called tunneling physics, Yang and his colleagues have produced a 25-nanometer transistor and recently figured out how to make one as small as 10 nanometers. At 10 nanometers, it would take some 100,000 transistors to span the width of a single human hair. Producing one of the transistors in the research lab is a slow process in which a computer directs a plasma beam to etch out the microscopic pattern for the transistor.
Transistors act as electrical switches that direct electrons around electronic circuits.
If the channel is too short, diffusion cannot be stopped, resulting in a transistor that is always on. Yang's transistor replaces the channel with a wall. By making it harder or easier for electrons to tunnel through the wall the transistor can be switched on or off. According to Yang, this new type of transistor can be smaller than conventional ones because the thickness of the wall can be much shorter than the minimum channel length needed for conventional transistors. However, the key to whether the new transistor technology is adopted by industry will depend on whether it can be mass produced and at a low-enough cost, Yang says.