What is said to be an ‘exotic material’ for next-gen electronics, a group of engineers from University of California, Riverside, have demonstrated prototype devices that can conduct a current density 50 times greater than the conventional copper interconnect technology.
The electronics industry is gradually arrogating beyond silicon and copper to develop devices that can resist extremely high current densities at sizes of just a few nanometers.
A group of researchers led by Alexander A. Balandin, a distinguished professor of electrical and computer engineering in the Marlan and Rosemary Bourns College of Engineering at UC Riverside, discovered that zirconium tritelluride, or ZrTe3, nanoribbons have an exceptionally high current density that far exceeds that of any conventional metals like copper.
The new strategy undertaken by the UC Riverside team pushes research from two-dimensional to one-dimensional materials — an important advance for the future generation of electronics.
“Conventional metals are polycrystalline. They have grain boundaries and surface roughness, which scatter electrons,” Balandin said. “Quasi-one-dimensional materials such as ZrTe3 consist of single-crystal atomic chains in one direction. They do not have grain boundaries and often have atomically smooth surfaces after exfoliation. We attributed the exceptionally high current density in ZrTe3 to the single-crystal nature of quasi-1D materials.”
In principle, such quasi-1D materials could be grown directly into nanowires with a cross-section that corresponds to an individual atomic thread, or chain. In the present study the level of the current sustained by the ZrTe3 quantum wires was higher than reported for any metals or other 1D materials. It almost reaches the current density in carbon nanotubes and graphene.
Electronic devices depend on special wiring to carry information between different parts of a circuit or system. As developers miniaturize devices, their internal parts also must become smaller, and the interconnects that carry information between parts must become smallest of all. Depending on how they are configured, the ZrTe3 nanoribbons could be made into either nanometer-scale local interconnects or device channels for components of the tiniest devices.
The UC Riverside group’s experiments were conducted with nanoribbons that had been sliced from a pre-made sheet of material.
Industrial applications need to grow nanoribbon directly on the wafer. This manufacturing process is already under development, and Balandin believes 1D nanomaterials hold possibilities for applications in future electronics.
“The most exciting thing about the quasi-1D materials is that they can be truly synthesized into the channels or interconnects with the ultimately small cross-section of one atomic thread — approximately one nanometer by one nanometer,” added Balandin.