Lawrence Berkeley National Laboratory has made a transistor with a 1nm gate using the two-dimensional material molybdenum disulphide, a carbon nanotube, and the insulator zirconium dioxide.
Berkeley Lab faculty scientist and UC Berkeley professor Ali Javey (left) and graduate student Sujay Desai – photo credit: Marilyn Chung/Berkeley Lab)
“We made the smallest transistor reported to date,” said principal investigator Ali Javey. “The gate length is considered a defining dimension of the transistor. We demonstrated a 1nm-gate transistor, showing that with the choice of proper materials, there is a lot more room to shrink our electronics.”
According to Berkeley Labs, short channel effects – quantum mechanical source-drain tunnelling prevents silicon transistors turning off if the gate is below 5nm. However, certain two-dimensional materials, including MoS2, maintain a uniform thickness down to a mono-layer, have low dielectric less than silicon, a larger bandgap, and heavier carrier effective mass.
“Here, we demonstrate MoS2 transistors with a 1nm physical gate length using a single-walled carbon nanotube as the gate electrode. These ultra-short devices exhibit excellent switching characteristics with near ideal sub-threshold swing of ~65mV/decade and an on-off current ratio of ~106. Simulations show an effective channel length of ~3.9nm in the Off state and ~1nm in the ‘on’ state,” said the research team in the abstract of Science paper ‘MoS2 transistors with 1-nanometer gate lengths‘.
More information available here.