A diagram of a three-dimensional indium-gallium-arsenide transistor (Image: Peter Ye, Purdue University)
Starting next year, computers will be available with three-dimensional transistors – these will incorporate vertical components, unlike the flat chips that we’re used to seeing. This structure will allow them to have shorter gates, which are the components that allow the transistors to switch the electrical current on and off, and to direct its flow. The shorter the gate, the faster the computer can operate. While the new 3D transistors will have a gate length of 22 nanometers, as opposed to the present length of about 45, the use of silicon as a construction material limits how much shorter they could ultimately get. That’s why scientists from Purdue and Harvard universities have created prototype 3D transistors made out of indium-gallium-arsenide – the same compound recently used in a record-breaking solar cell.