Small wonder
A team of researchers — including electrical engineering and computer sciences professors Ali Javey, Jeff Bokor, Chenming Hu and graduate student Sujay Desai — has created the world’s smallest transistor. Although transistors have been getting smaller, scientists had long thought there were specific size limitations. Transistors rely on the flow of electric current through a semiconducting channel; this current is controlled by a terminal called the gate. In silicon — the material of choice for commercial transistors today — when the gate is smaller than 5 nanometers, the current cannot be controlled due to a quantum mechanical effect called tunneling. But by changing the channel material from silicon, the researchers built a transistor with a working 1-nanometer gate. They achieved this by using carbon nanotubes, naturally grown as 1-nanometer diameter tubes, as the gate and molybdenum disulfide, an engine lubricant commonly sold in auto parts shops, as the semiconducting channel. This development could be key to advancing the scaling of transistors as well as the performance and efficiency of electronics. “We made the smallest transistor reported to date,” says Javey. “We demonstrated a 1-nanometer gate transistor, showing that with the choice of proper materials, there is a lot more room to shrink our electronics.”