Monday, May 07, 2007

US Patent 7211853 - Nanotube FET

There has been some speculation as to whether Moore's law (referring to the exponential increase in transistor density over time) will eventually require nanotube FETs (FET= field effect transistor). Several companies already have patents on this technology and one might ask the question of whether there is a fundamental nanotube FET out there. This patent is assigned to a European University ( which makes a claim with priority going back to July 26, 2001. Claim 1 reads:

1. An electronic device comprising a tubular shaped carbon molecule supported by a substrate, which molecule is provided with source and drain electrodes directly contacting said carbon molecule, as well as a gate electrode, wherein the gate electrode is a metallic electrode.

However, the Examiner may have overlooked some relevant prior art such as

US 6566704 (

which has U.S. filing priority going back to June 27, 2001 and is owned by Samsung. This patent provides a basic claim to a vertical carbon nanotube transistor. Claim 1 reads:

1. A vertical nano-sized transistor using carbon nanotubes comprising: an insulating layer having holes, the holes having nano-sized diameters; carbon nanotubes vertically aligned in the holes; gates formed over the insulating layer in the vicinity of the carbon nanotubes; a nonconductor film deposited on the gates to fill the holes; drains formed over the nonconductor film and the carbon nanotubes; and sources formed under the insulating layer and the carbon nanotubes.

or perhaps this article from IBM published in 1998 may shed some light on the validity of this patent (see Fig. 1)

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