Currents cross virtual outer-space in transistor air gap

Researchers have developed a transistor that sends electrical currents through narrow air gaps instead of through silicon.  

The proof-of-concept, developed by a team at RMIT University in Australia, recreates a virtual outer space for electrons to travel through. The technology is faster, less prone to overheating, and eliminates the use of a semiconductor in electronics.

Lead author in EMIT’s Functional Materials and Microsystems Research Group Shruti Nirantar: “Every computer and phone has millions to billions of electronic transistors made from silicon, but this technology is reaching its physical limits where the silicon atoms get in the way of the current flow, limiting speed and causing heat.

“Our air channel transistor technology has the current flowing through air, so there are no collisions to slow it down and no resistance in the material to produce heat.”

RMIT Associate Professor Sharath Sriram said traditional solid channel transistors are packed with atoms, meaning electrons passing through them collide, slow down, and waste energy.  The new design creates a nanoscale gap between two metal points to travel unimpeded “as if in space”.

“The gap is only a few tens of nanometres, or 50,000 times smaller than the width of a human hair, but it’s enough to fool electrons into thinking that they are travelling through a vacuum and recreate a virtual outer-space for electrons within the nanoscale air gap,” Sriram said.

The number of transistors on a silicon chip has roughly doubled every two years, but recently engineers are struggling to make transistor parts smaller. RMIT’s nanoscale device is compatible with modern industry fabrication and development processes to overcome the limitations of silicon-based electronics.

The research by RMIT University was conducted at its Micro Nano Research Facility and published in material sciences journal Nano Letters.