Carbon Nanotube Complementary Wrap-Gate Transistors

Abstract

Among the challenges hindering the integration of carbon nanotube (CNT) transistors in digital technology are the lack of a scalable self-aligned gate and complementary n- and p-type devices. We report CNT transistors with self-aligned gates scaled down to 20 nm in the ideal gate-all-around geometry. Uniformity of the gate wrapping the nanotube channels is confirmed, and the process is shown not to damage the CNTs. Further, both n- and p-type transistors were realized by using the appropriate gate dielectric-HfO2 yielded n-type and Al2O3 yielded p-type-with quantum simulations used to explore the impact of important device parameters on performance. These discoveries not only provide a promising platform for further research into gate-all-around CNT devices but also demonstrate that scalable digital switches with realistic technological potential can be achieved with carbon nanotubes.

Nanomaterials in transistors: From high-performance to thin-film applications

“…For instance, nucleating the growth of highquality dielectrics (insulating barriers) with atomic layer deposition (ALD) is problematic for nanomaterials, as they do not offer typical end groups for reacting with the ALD precursors. Creative solutions have been presented for potentially addressing the creation of high-quality dielectric interfaces (72)(73)(74)(75), but there has been much less progress on improving the contact metal interfaces. Regardless of whether a nanomaterial transistor is for high-performance or thin-film applications, the device will depend heavily on the quality of transport at the source and drain metal contact interfaces.…”

End-bonded contacts for carbon nanotube transistors with low, size-independent resistance

“…We have only demonstrated p-channel SWNT transistors using p-type end contacts. It will be difficult to form end-bonded n-type contacts to SWNTs in which electrons are directly injected into the conduction band of SWNTs with this carbide formation approach, as metals with low enough work function tend to oxidize first rather than react with C. However, it is still possible to realize n-channel SWNT device operation even with end-bonded contacts to high work function metals through electrostatic doping in the vicinity of the source electrode (10,38). …”

A Semiphysical Large-Signal Compact Carbon Nanotube FET Model for Analog RF Applications

“…sistors (CNTFETs) possess a number of properties that may make CNTFET technologies well suitable for certain applications [1], [3], [4]. In particular, the 1-D transport in carbon nanotubes (CNTs) leads not only to a low scattering rate and high current-carrying capability but also to a linear relation between drain current and input (gate-source) voltage under specific conditions [5]- [7].…”