*****For immediate use September 19, 2003
Tests Verify Carbon Nanotube Enable Ultra High Performance Transistor
- 10 times greater transconductance than silicon demonstrated -
TOKYO, September 19, 2003 - NEC Corporation today announced development of stable fabrication technology for carbon nanotube (note 1) transistors. Through this development NEC verified that CNT transistors produced by using this fabrication technology attain more than 10 times greater transconductance (note 2) than silicon MOS transistors.
This result was achieved through the development of the following key technology.
(1) Development of chemical vapor deposition using a catalyst method that creates CNT growth from the position of the catalyst on the silicon substrate. This technology enables control of the CNT position on the silicon substrate whereas conventional fabrication processes cannot.
(2) Development of a process for the formation of electrodes which realizes low contact resistance between the electrodes and the CNT. This technology dramatically reduces the electric resistance between the CNT and the electrode contact parts.
Through the development of the above key technologies stable fabrication of CNT transistors was demonstrated. From the characterization of these transistors, it was also ascertained that it will be possible to achieve as much as 20 times greater transconductance as compared with silicon MOS transistors by removing the parasitic resistance between the electrodes (source and drain).
The results of this research hold great potential for CNT transistors as high-performance electrical devices supporting a future ubiquitous IT society. NEC will continue to work on advancements in CNT control technology, electric characteristic control, device structure design, and fabrication process development with the aim of realizing a CNT transistor by 2010.
This result will be announced at the 2003 International Conference on Solid State Devices and Materials being held from September 16 to 18 in Tokyo. Japan Fine Ceramics Center (JFCC) and the New Energy and Industrial Technology Development Organization (NEDO) commissioned this research as a part of the Nanocarbon Application Product Creation Technology Project.
About NEC Corporation
NEC Corporation (NASDAQ: NIPNY) (FTSE: 6701q.l) is one of the world's leading providers of Internet, broadband network and enterprise business solutions dedicated to meeting the specialized needs of its diverse and global base of customers. Ranked as one of the world's top patent-producing companies, NEC delivers tailored solutions in the key fields of computer, networking and electron devices, by integrating its technical strengths in IT and Networks, and by providing advanced semiconductor solutions through NEC Electronics Corporation. The NEC Group employs more than 140,000 people worldwide and had net sales of approximately $40 billion in the fiscal year ended March 2003. For additional information, please visit the NEC home page at: http://www.nec.com.
CNT is nanometer sized carbon crystal with a cylindrical structure that was discovered by Dr. Sumio Iijima in 1991. The electrical and physical characteristics that the material possesses are attracting great attention, and fundamental and applied research are being pro-actively carried out. Despite its small diameter, large electric currents can be passed through a CNT. It is predicted, in regards to applications in the electronics field, that it will create greater electron velocity than silicon which is currently used in LSIs. It is expected that this will enable ultra high-speed operation when applied to the channel part of the transistor.
Transconductance is an index to measure the performance of a transistor. It shows how large a change in output drain current is obtained as a result of a change in input gate voltage. The larger this value the greater the operation speed of the transistor.
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