The current-carrying and heat-transfer measurements were reported by a team of researchers from the Georgia Institute of Technology. The same team had previously reported measurements of resistivity in graphene that suggest the material’s conductance would outperform that of copper in future generations of nanometer-scale interconnects.
“Graphene nanoribbons exhibit an impressive breakdown current density that is related to the resistivity,” said Raghunath Murali, a senior research engineer in Georgia Tech’s Nanotechnology Research Center. “Our measurements show that these graphene nanoribbons have a current carrying capacity at least two orders of magnitude higher than copper at these size scales.”
Measurements of thermal conductivity and breakdown current density in narrow graphene nanoribbons were reported June 19 in the journal Applied Physics Letters. The research was supported by the Semiconductor Research Corporation/DARPA through the Interconnect Focus Center and by the Nanoelectronics Research Initiative through the Institute for Nanoelectronics Discovery and Exploration (INDEX).
The unique properties of graphene – which is composed of thin layers of graphite – make it attractive for a wide range of potential electronic devices. Murali and his colleagues have been studying graphene as a potential replacement for copper in on-chip interconnects, the tiny wires that are used to connect transistors and other devices on integrated circuits. Use of graphene for these interconnects, they believe, would help extend the long run of performance improvements in integrated circuit technology.
“Our measurements show that graphene nanoribbons have a current carrying capacity of more than 10^8 amps per square centimeter, while a handful of them exceed 10^9 amps per square centimeter,” Murali said. “This makes them very robust in resisting electromigration and should greatly improve chip reliability.”
Electromigration is a phenomenon that causes transport of material, especially at high current density. In on-chip interconnects, this eventually leads to a break in the wire, which results in chip failure.
“We are learning a lot of new things about this material, which will lead researchers to consider other potential applications,” said Murali. “In addition to the high current carrying capacity, graphene nanoribbons also have excellent thermal conductivity.”
Because heat generation is a significant cause of device failure, the researchers also measured the ability of the graphene nanostructures to conduct heat away from devices. They found that graphene nanoribbons have a thermal conductivity of more than 1,000 watts per meter Kelvin for structures less than 20 nanometers wide.
“This high thermal conductivity could allow graphene interconnects to also serve as heat spreaders in future generations of integrated circuits,” said Murali.
To study the properties of graphene interconnects, Murali and collaborators Yinxiao Yang, Kevin Brenner, Thomas Beck and James Meindl began with flakes of multi-layered graphene removed from a graphite block and placed onto an oxidized silicon substrate. They used electron beam lithography to construct four electrode contacts, then used lithography to fabricate devices consisting of parallel nanoribbons of widths ranging between 16 and 52 nanometers and lengths of between 0.2 and 1 micron.
The breakdown current density of the nanoribbons was then studied by slowly applying an increasing amount of current to the electrodes on either side of the parallel nanoribbons. A drop in current flow indicated the breakdown of one or more of the nanoribbons.
In their study of 21 test devices, the researchers found that the breakdown current density of graphene nanoribbons has a reciprocal relationship to the resistivity.
Because graphene can be patterned using conventional chip-making processes, manufacturers could make the transition from copper to graphene without a drastic change in chip fabrication.
“Graphene has very good electrical properties,” Murali said. “The data we have developed so far looks very promising for using this material as the basis for future on-chip interconnects.”
John Toon | Newswise Science News
Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory
SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences