A leap toward more powerful and efficient computer chips

The discovery, published in Nature Communications and supported by the Semiconductor Research Corporation in partnership with Intel, provides critical insights into heat management in next-generation chips. This breakthrough offers the potential to design faster, smaller, and more efficient devices, addressing long-standing thermal challenges in electronics.

“As devices continue to shrink, the importance of managing heat becomes paramount,” said Md. Rafiqul Islam, lead researcher and Ph.D. student in mechanical and aerospace engineering. “Consider high-end gaming consoles or AI-driven data centres, where constant, high-power processing often leads to thermal bottlenecks. Our findings provide a blueprint to mitigate these issues by refining the way heat flows through ultra-thin metals like copper.”

Heat at the nanoscale: unravelling the science

Copper, widely used in electronics for its excellent conductivity, encounters unique challenges as devices scale down to nanometre dimensions. At such small scales, heat management becomes critical as increased electron scattering leads to diminished thermal conductivity. To address this, the UVA team focused on validating Matthiessen’s rule – a principle that predicts how different scattering mechanisms affect electron and heat flow.

Although Matthiessen’s rule has long been used to model heat and electron behaviour in bulk materials, its applicability to nanoscale materials was previously unconfirmed. The UVA researchers demonstrated that this rule holds true for ultra-thin copper films using a novel measurement technique called steady-state thermoreflectance (SSTR).

By cross-referencing thermal conductivity data with electrical resistivity measurements, the team verified that Matthiessen’s rule accurately describes heat behaviour in copper films at nanoscale thicknesses.

Implications for cooler, faster chips

In the context of very-large-scale integration (VLSI) technology – where millions of transistors are packed into minuscule spaces – effective heat management directly impacts performance and energy efficiency. The UVA team’s findings pave the way for optimising materials like copper to improve heat dissipation in advanced chips.

“Think of it as a roadmap,” explained Patrick E. Hopkins, Whitney Stone Professor of Engineering and Islam’s adviser. “With the validation of this rule, chip designers now have a trusted guide to predict and control how heat will behave in tiny copper films. This is a game-changer for making chips that meet the energy and performance demands of future technologies.”

The ability to design materials with predictable thermal properties ensures devices not only run cooler but also lose less energy to heat – addressing sustainability concerns in modern electronics.

Bridging academia and industry

The study highlights the value of collaboration between academic researchers and industry leaders. Conducted with support from the Semiconductor Research Corporation and Intel, the findings are poised to influence the development of complementary metal-oxide-semiconductor (CMOS) technology, the foundation of today’s electronic devices.

By combining experimental data with advanced modelling, the research sets a new benchmark for material performance in next-generation chips. These advancements could lead to significant energy savings across the industry while improving the efficiency and lifespan of devices ranging from smartphones to AI-powered servers.

The study, titled ‘Evaluating size effects on the thermal conductivity and electron-phonon scattering rates of copper thin films for experimental validation of Matthiessen’s rule’, was authored by Md. Rafiqul Islam and Patrick E. Hopkins. Published in Nature Communications on 3rd December 2024, it marks a milestone in understanding heat management at the nanoscale.