NEW ORLEANS – Researchers at Stanford University have developed an ultrathin material, niobium phosphide (NbP), that surpasses copper in electrical conductivity at nanometer-scale thicknesses. This advancement could significantly enhance the performance and energy efficiency of nanoelectronic devices, particularly in data centers and high-performance computing systems.​
According to Stanford University, unlike copper, which loses conductivity when reduced below 50 nanometers, NbP exhibits improved conductivity as it becomes thinner. This property is attributed to its classification as a topological semimetal, where the material’s surface conducts electricity more effectively than its interior. As the film thins, the proportion of conductive surface area increases, enhancing overall conductivity.​
“We are breaking a fundamental bottleneck of traditional materials like copper,” said Asir Intisar Khan, a postdoctoral researcher at Stanford University and an author on the research paper. “Our niobium phosphide conductors show that it’s possible to send faster, more efficient signals through ultrathin wires. This could improve the energy efficiency of future chips, and even small gains add up when many chips are used, such as in the massive data centers that store and process information today.”​
The NbP films can be fabricated at relatively low temperatures (around 400°C), making them compatible with existing silicon-based chip manufacturing processes. This means that can be deposited into modern computer chip fabrication. This contrasts with other materials that require high-temperature conditions to form precise crystalline structures, which can be detrimental to silicon components.​
This development is important for future telecommunications, cell phone, and data center businesses and customers because it addresses a critical challenge in modern electronics: energy loss and signal degradation in nanoscale connections. As devices become smaller and more powerful, they rely on increasingly thin metal interconnects to transmit electrical signals.
“Really high-density electronics need very thin metal connections, and if those metals are not conducting well, they are losing a lot of power and energy,” said Stanford professor Eric Pop, senior author of the study. “Better materials could help us spend less energy in small wires and more energy actually doing computation.”​
At thicknesses below 5 nanometers, NbP films have demonstrated electrical resistivity significantly lower than that of copper. For instance, at 1.5 nanometers, NbP’s resistivity is approximately 34 microohm-centimeters, compared to copper’s 100 microohm-centimeters at similar scales.​
“It has been thought that if we want to leverage these topological surfaces, we need nice single-crystalline films that are really hard to deposit,” said doctoral student and paper co-author Akash Ramdas. “Now we have another class of materials — these topological semimetals — that could potentially act as a way to reduce energy usage in electronics.”​
The development of NbP as a conductor addresses the limitations of copper in nanoscale applications, offering a pathway to more efficient and powerful electronic devices. For telecommunications infrastructure, this means better-performing switches and routers that can handle growing internet traffic with less power consumption. In cell phones, more efficient interconnects can contribute to longer battery life and faster processing speeds. And in data centers, which consume massive amounts of electricity, substituting copper with niobium phosphide in key parts of chip architecture could lower energy costs and improve processing throughput.
These increases in efficiency could have a profound impact on the cost and speed relating to the complete range of communications devices.
