- 07 September 2006 -

IEDM Showcases Forest of InAs Nanowires from Lund University

The annual IEDM presents some of the best applied research in electronics from labs around the world. Included in some of the most interesting papers to be given at the 52nd annual meeting, December 11 - 13, 2006 at the San Francisco, CA Hilton are some on advanced semiconductors including III-Vs. The meeting will be preceded by a day of Short Courses on Sunday, Dec. 10.



For example, a ‘Forest of Nanowires’ from researchers at Sweden's Lund University* who built a MOSFET using an air-bridge design with a 10x10 vertical array of InAs nanowires as the channel. Electrons flow through InAs extremely fast, and so this structure promises excellent performance. Electron mobilities through the array may be as high as 10000 cm2/Vs, and drive current of 100µA and transconductance of 2 mS were measured at zero gate voltage.

The nanowires were 1 µm apart, grown by chemical beam epitaxy on lithographically defined gold disks on a substrate, which acted as catalysts for their growth. The disks were patterned using electron-beam lithography. All other patterning was accomplished with conventional optical lithography and standard III-V processing techniques. A wrap-gate dielectric and the gold disks were formed from low-temperature CVD-deposited SiN and sputtered Ti/Au, respectively.

The electron microscope images show here detail this work. At left is a view of a matrix of InAs nanowires with the wrap-gate formed, while at right a completed transistor with gate/drain pads and air-bridge is shown.

*Paper #11.5, "Wrap-Gated InAs Nanowire Field Effect Transistor," L-E Wernersson et al, University of Lund.

lew@gandalf.ftf.lth.se