New Semiconductor Material Reduces Heat and Boosts Performance of Computer Processors

Engineers from the University of California, Los Angeles (UCLA), have successfully incorporated a new semiconductor material into a high-power computer chip to reduce the build-up of heat on processors and thus enhance their performance.

This latest development significantly boosts energy efficiency in computers and prevents heat build-up beyond the most optimal thermal-management devices available today. The study was headed by Yongjie Hu, an associate professor of mechanical and aerospace engineering at the UCLA Samueli School of Engineering.

The study has been recently published in the Nature Electronics journal.

Over the years, the size of computer processors has been reduced to nanometer scales, with scores of transistors integrated into a single computer chip. Although the high number of transistors increases the speed and power of computers, they tend to create more hot spots in a highly condensed space.

When there is no efficient way to dissipate heat at the time of operation, computer processors can slow down and lead to inefficient and unreliable computing. Moreover, the increasing temperatures combined with the highly concentrated heat on computer chips also need additional energy to prevent the overheating of processors.

To solve this issue, Hu and his research team invented a novel ultrahigh thermal-management material back in 2018. They developed defect-free boron arsenide in the laboratory and found it to be relatively more effective in terms of drawing and dissipating heat when compared to other familiar metals or semiconductor materials, like silicon carbide and diamond.

Now, for the first time, the researchers have successfully revealed the effectiveness of the new material by incorporating it into high-powered devices.

During their experiments, the team used computer chips with advanced wide bandgap transistors — known as high-electron-mobility transistors (HEMTs) — composed of gallium nitride.

When the processors were run at near-maximum capacity, the computer chips — using boron arsenide as a heat spreader — had the highest heat increase, that is, from room temperatures to almost 188 °F. This is much lower than the chips using diamond to dissipate heat, with temperatures increasing to about 278 °F, or the ones using silicon carbide and showing a heat increase of around 332 °F.

These results clearly show that boron-arsenide devices can sustain much higher operation power than processors using traditional thermal-management materials. And our experiments were done under conditions where most current technologies would fail. This development represents a new benchmark performance and shows great potential for applications in high-power electronics and future electronics packaging.

Yongjie Hu, Associate Professor of Mechanical and Aerospace Engineering, UCLA Samueli School of Engineering

Hu believes that boron arsenide is perfect for managing heat because it not only displays excellent thermal conductivity but also has low heat-transport resistance.

When heat crosses a boundary from one material to another, there's typically some slowdown to get into the next material. The key feature in our boron arsenide material is its very low thermal-boundary resistance. This is sort of like if the heat just needs to step over a curb, versus jumping a hurdle.

Yongjie Hu, Associate Professor of Mechanical and Aerospace Engineering, UCLA Samueli School of Engineering

In addition, the team has produced boron phosphide as another remarkable heat-spreader candidate. In their experiments, the investigators first demonstrated a method to construct a semiconductor structure using boron arsenide and subsequently embedded the material into the HEMT chip. The project's success can lead to the industrial adoption of the technology.

Journal Reference:

Kang, J. S., et al. (2021) Integration of boron arsenide cooling substrates into gallium nitride devices. Nature Electronics. doi.org/10.1038/s41928-021-00595-9.