Graphene or carbon nanotube devices with localized bottom gates and gate dielectric

Abstract

Transistor devices having nanoscale material-based channels (e.g., carbon nanotube or graphene channels) and techniques for the fabrication thereof are provided. In one aspect, a transistor device is provided. The transistor device includes a substrate; an insulator on the substrate; a local bottom gate embedded in the insulator, wherein a top surface of the gate is substantially coplanar with a surface of the insulator; a local gate dielectric on the bottom gate; a carbon-based nanostructure material over at least a portion of the local gate dielectric, wherein a portion of the carbon-based nanostructure material serves as a channel of the device; and conductive source and drain contacts to one or more portions of the carbon-based nanostructure material on opposing sides of the channel that serve as source and drain regions of the device.

Description

[0001] Statement of Government Rights [0002] This invention was made with Government support under Contract No. FA8650-08-C-7838 assigned by the Defense Advanced Research Projects Agency (DARPA). The government has certain rights in this invention. technical field [0003] The present invention relates to transistor devices, and more particularly to transistor devices having channels based on nanoscale materials, such as carbon nanotube or graphene channels, and techniques for fabricating the devices. Background technique [0004] Integrating carbon nanostructures as channel materials in next-generation electronic devices could offer numerous benefits over continued scaling down of silicon (Si). Carbon nanotubes and graphene are two nanoscale forms of carbon that exhibit extremely high current carrying capacity and mobility several orders of magnitude beyond the theoretical limit for Si. Furthermore, carbon nanotubes (one-dimensional) and graphene (two-dimensional) are l...

AI Technical Summary

Problems solved by technology

However, molecular layers have been shown to interact with carbon bonds, thereby creating scattering centers that cause substantial impairment of mobility

In fact, since all carriers are located on the surface of these nanostructures, the carriers are strongly coupled to any material deposited around them, causing degradation in transport properties

Furthermore, when molecules such as deoxyribonucleic acid (DNA) are used to create the nucleation layer around carbon nanotubes, uniformity suffers due to the large molecular diameter (4nm for DNA) compared to carbon nanotubes (about 1.5nm). got damage

The latter two methods do not provide a solution for scaling down the dielectric thickness, i.e. dielectric thickness from 8nm to about 15nm is required to ensure complete coverage of the carbon surface

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