Home > Press > Carbon Nanotubes and Semiconductor Nanowires for Microelectronics
The continuous downscaling of feature sizes in microelectronics according to Moore's law has already required the introduction of several "non-conventional" materials into the semiconductor manufacturing industry in recent years, such as Cu, high- and low- k dielectrics, etc.
Carbon Nanotubes and Semiconductor Nanowires for Microelectronics
UK | Posted on December 9th, 2009
For very advanced technology nodes (i.e.towards the 16nm node), bottom-up grown nanomaterials are also being considered for their potential as building blocks of devices and interconnections. Nanomaterials would not necessarily directly contribute to higher device densities, but their unique properties may solve specific issues linked to downscaling and would certainly enable a number of new device concepts and architectures.
Carbon Nanotubes (CNTs) and semiconductor Nanowires (NWs) are generally bottomup grown in a catalysed chemical vapour deposition (CCVD) fashion, i.e. with the mediation of metal nanoparticles. The formation of such nanoparticles by breaking up a thin catalyst film on the substrate, and the particle pre-growth treatment are key steps of the global growth process, which would literally only start when the precursor gases are brought into the chamber (Fig.1).
For microelectronics applications, it is essential that the growth process stays compatible with Si technology in terms of materials, tools and processes used, and also that it can be realised on wafer -scale. CNTs are mostly being considered as possible interconnects material, as replacement of Cu interconnects. The characteristic ballistic conduction of metallic CNTs, together with their high thermal conductivity (about 6000 W K m-1, compared to 400 W K m-1 for Cu), makes them particularly interesting for vertical interconnects in small vias (10 nm diameter and below) with high aspect ratios. The most favourable configuration would be the growth of high density single wall carbon nanotubes, although also multi-wall nanotubes would lead to an improvement as compared to Cu.
As shown in Fig.2, a high density (~1012 CNTs/cm2) carpet of aligned CNTs with a few nm diameter was grown at 650ºC in a PlasmalabSystem100, starting from a Fe/Ti bilayer catalyst. The plasma pre-treatment of the particles is key to such high density growth.
Semiconductor nanowires are ideal building blocks for both logics and memory devices. Their vertical wire geometry allows excellent control on the electrical field in the channel of a nanowire-based transistor thanks to the all-around gate. Also, the growth of segmented nanowires would enable the formation of high quality hetero-junctions of mismatched semiconductors, thanks to favourable elastic and plastic relaxation phenomena at the nanoscale. On the other hand, NWs are generally grown using Au catalyst particles. Au is a killer impurity in Si technology, and trials to use other metal catalysts have not been as successful. In Fig.3 we show the feasibility of Si NWs growth from indium nanoparticles, again in a PlasmalabSystem100. Indium is not an efficient chemical catalyst for the Si precursor dissociation, so the use of plasma-enhanced CVD growth, following a plasma-based particle pre-growth treatment of the In particles, is essential for a successful In -mediated nanowire growth.
Author: Francesca Iacopi, PhD, Senior Scientist, IMEC
(see full release for all three figures)
About Oxford Instruments
Oxford Instruments is a worldwide business supplying high technology tools and systems for the analysis and manipulation of matter at the smallest scale. Our diverse markets include industrial analysis, research, education, space, and energy.
For more information, please click here
Copyright © Oxford Instruments
If you have a comment, please Contact
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
News and information
Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014
'Life Redesigned: The Emergence of Synthetic Biology' Lecture at Brookhaven Lab on Wednesday, April 30: Biomedical Engineer James Collins to Speak for BSA Distinguished Lecture Series April 16th, 2014
ECHA Planning Workshop on Regulatory Challenges in the Risk Assessment of Nanomaterials April 16th, 2014
Lumerical files a provisional patent that extends the standard eigenmode expansion propagation technique to better address waveguide component design. Lumerical’s EME propagation tool will address a wide set of waveguide applications in silicon photonics and integrated optics April 16th, 2014
Industry Veteran Fergus Clarke Joins Picodeon as CEO: Appointment comes as Picodeon prepares for growth April 8th, 2014
Scalable CVD process for making 2-D molybdenum diselenide: Rice, NTU scientists unveil CVD production for coveted 2-D semiconductor April 8th, 2014
High-quality nanometric bilayers prepared by aqueous solutions March 26th, 2014
A new concept for manufacturing wrinkling patterns on hard-nano-film/soft-matter-substrate March 24th, 2014
Scientists open door to better solar cells, superconductors and hard-drives: Research enhances understanding of materials interfaces April 14th, 2014
Obducat has launched a new generation of SINDRE® Nano Imprint production system April 11th, 2014
Scientists in Singapore develop novel ultra-fast electrical circuits using light-generated tunneling currents April 10th, 2014
Clean Shot at Manufacturing Course…For Less April 9th, 2014
Effects of Carbon Nanotubes Studied on Pregnant Mothers April 12th, 2014
Nanotech Business Review 2013-2014 April 9th, 2014
Scientists Succeed in Simultaneous Determination of Acetaminophen, Codeine in Drug Samples April 9th, 2014
Rebar technique strengthens case for graphene: Rice University lab makes hybrid nanotube-graphene material that promises to simplify manufacturing April 7th, 2014
Better solar cells, better LED light and vast optical possibilities April 12th, 2014
Catching the (Invisible) Wave: UC Santa Barbara researchers create a unique semiconductor that manipulates light in the invisible infrared/terahertz range, paving the way for new and enhanced applications April 11th, 2014
Nanotech Business Review 2013-2014 April 9th, 2014
Preview of Hands-on Nanotechnology Demos at ‘Chemistry of Wine’ Fundraiser to Show Nanotech Magic April 8th, 2014