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PUBLISHED ONLINE: 21 FEBRUARY 2010 | http://www.nature.com/doifinder/10.1038/nnano.2010.15
Web End =DOI: 10.1038/NNANO.2010.15
Nanowire transistors without junctions
Jean-Pierre Colinge*, Chi-Woo Lee, Aryan Afzalian, Nima Dehdashti Akhavan, Ran Yan, Isabelle Ferain, Pedram Razavi, Brendan ONeill, Alan Blake, Mary White, Anne-Marie Kelleher,
Brendan McCarthy and Richard Murphy
All existing transistors are based on the use of semiconductor junctions formed by introducing dopant atoms into the semiconductor material. As the distance between junctions in modern devices drops below 10 nm, extraordinarily high doping concentration gradients become necessary. Because of the laws of diffusion and the statistical nature of the distribution of the doping atoms, such junctions represent an increasingly difcult fabrication challenge for the semiconductor industry. Here, we propose and demonstrate a new type of transistor in which there are no junctions and no doping concentration gradients. These devices have full CMOS functionality and are made using silicon nanowires. They have near-ideal subthreshold slope, extremely low leakage currents, and less degradation of mobility with gate voltage and temperature than classical transistors.
All existing transistors are based on the formation of junctions.
Junctions are capable of both blocking current and allowing it to ow, depending on an applied bias. They are typically
formed by placing two semiconductor regions with opposite polarities into contact with one another. The most common junction is the pn junction, which consists of a contact between a p-type piece of silicon, rich in holes, and an n-type piece of silicon, rich in electrons. Every textbook on semiconductor device physics contains a chapter on the pn junction, usually between the introductory chapters on semiconductor material fundamentals and the chapters dedicated to the different types of transistors.Other types of junctions include the metalsilicon Schottky junction and the heterojunction, which is a pn junction comprising two different semiconductor materials. The bipolar junction transistor contains two pn junctions, and so does the MOSFET (metal-oxidesemiconductor eld-effect transistor). The JFET (junction eld-effect transistor) has only one pn junction and the MESFET (metalsemiconductor eld-effect transistor) contains a Schottky junction.
The rst patent1 for the transistor principle was led in Canada by Austrian-Hungarian physicist Julius Edgar Lilieneld on 22 October 1925. He patented the device in the United States a few years later under the title Device for controlling electric current2, but he never...