Nature 468, 286–289 (2010)
Silicon dominates the electronics industry but III–V semiconductors such as indium arsenide offer faster switching speeds and better optical properties. It is possible to make devices that contain both silicon and a III–V semiconductor, but defects and leakage currents cause problems. Now researchers in the United States and Taiwan have made high-performance nanoscale transistors by transferring nanoribbons of indium arsenide onto a silicon substrate.
Ali Javey and co-workers used epitaxy and etching to produce the nanoribbons on a GaSb substrate. The nanoribbons were then removed with a flexible substrate and transferred to a Si/SiO2 substrate using a stamping process. An insulating layer of ZrO2 was then added, followed by nickel electrodes. The quality of the interfaces between the nanoribbon and the dielectric layers above and below, and hence device performance, was improved by thermally oxidizing the InAs to produce a 1-nm layer of InAsOx.
The team made transistors in which the nanoribbons were as thin as 8 nm, and explored how the performance varied with the thickness. And by using a two-step process to transfer an array of 18-nm-thick nanoribbons, and then place an array of 48-nm-thick nanoribbons at right angles to the first array, Javey and co-workers demonstrated the potential of their approach to make a variety of semiconductor devices.