be needed to continue progress, Ye says. Creating smaller transistors also will require finding a new type of insulating, or “dielectric” layer that allows the gate to switch off. As gate lengths shrink smaller than 14 nm, the dielectric used in conventional transistors fails to perform properly and is said to “leak” electrical charge when the transistor is turned off.
Nanowires in the new transistors are coated with a different type of composite insulator, a 4 nm thick layer of lanthanum aluminate with an ultrathin, half-nanometre layer of aluminium oxide. The new ultrathin dielectric allowed researchers to create transistors made of InGaAs with 20 nm gates, which is a milestone, Ye continues.
The work, based at the Birck Nanotechnology Center in Purdue’s Discovery Park, was funded by the National Science Foundation and the Semiconductor Research Corp.