The Smallest Transistor
A research team led by faculty scientist Ali Javey at the Department of Energy’s Lawrence Berkeley National Laboratory has created a transistor with a working 1-nanometer gate.
“We made the smallest transistor reported to date,” said Javey, lead principal investigator of the Electronic Materials program in Berkeley Lab’s Materials Science Division. “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.”
The key was to use carbon nanotubes and molybdenum disulfide (MoS2), an engine lubricant commonly sold in auto parts shops. The findings were published today in the journal Science. The development could be key to keeping alive Intel co-founder Gordon Moore’s prediction that the density of transistors on integrated circuits would double every two years.
Both silicon and MoS2 have a crystalline lattice structure, but electrons flowing through silicon are lighter and encounter less resistance compared with MoS2. That is a boon when the gate is 5 nanometers or longer. But below that length, a quantum mechanical phenomenon called tunneling kicks in, and the gate barrier is no longer able to keep the electrons from barging through from the source to the drain terminals.
Once they settled on MoS2 as the semiconductor material, it was time to construct the gate. Making a 1-nanometer structure, it turns out, is no small feat. Conventional lithography techniques don’t work well at that scale, so the researchers turned to carbon nanotubes, hollow cylindrical tubes with diameters as small as 1 nanometer.
They then measured the electrical properties of the devices to show that the MoS2transistor with the carbon-nanotube gate effectively controlled the flow of electrons.
“This work demonstrated the shortest transistor ever,” said Javey.
This article is published on ‘The PCB Design Magazine’ Oct., 2016. If you are interested, just google it.