β-Ga₂O₃-on-Diamond

β-Ga₂O₃-on-Diamond: The Next Frontier of Thermal Management₃-on-Diamond: The Next Frontier of Thermal Management

From Heat Removal to Heat Integration

As power semiconductor technologies enter the era of ultra-wide-bandgap materials, thermal management is rapidly becoming the primary limitation to further performance scaling. While β-Ga₂O₃ offers exceptional electrical characteristics, its relatively low thermal conductivity creates significant challenges in high-power operation.

At DIASEMI, we believe the future is not simply attaching a heatsink beneath a device—it is integrating thermal management directly into the semiconductor architecture itself.

Recent breakthroughs in β-Ga₂O₃-on-diamond heteroepitaxy provide compelling evidence that diamond is evolving from a passive thermal spreader into an active semiconductor platform.

Diamond: The Ultimate Thermal Foundation

With thermal conductivity approaching 2200 W/m·K, CVD diamond remains the most effective thermal material available for electronic applications. Integrating power devices directly onto diamond enables heat to be extracted at its source, dramatically reducing thermal resistance and hotspot formation.

The challenge has always been the interface.

Traditional bonding and deposition techniques often suffer from weak adhesion, interfacial defects, and high thermal boundary resistance, limiting the full potential of diamond-enabled cooling.

A Breakthrough in Atomic-Level Integration

Researchers have demonstrated a novel gallium-assisted epitaxial growth process that directly integrates β-Ga₂O₃ onto diamond substrates.

The resulting structure exhibits:

• Atomically smooth β-Ga₂O₃/diamond interfaces • Direct C–O covalent bonding across the interface • Interfacial fracture strength exceeding 2.09 GPa • Thermal boundary conductance of 165.4 MW/m²·K • Thermal boundary resistance as low as 6.05 m²·K/GW

These values represent one of the most efficient thermal interfaces ever reported between β-Ga₂O₃ and diamond.

The Discovery of a "Phonon Bridge"

Perhaps the most exciting finding is the identification of a previously unknown interfacial phonon mode near 60 meV.

This unique vibrational state acts as a bridge between the phonon spectra of diamond and β-Ga₂O₃, enabling more efficient energy transfer across the interface.

In simple terms, the interface is no longer a thermal barrier—it becomes a thermal gateway.

This discovery opens new opportunities for engineering ultra-low-resistance thermal interfaces for next-generation power electronics.

What This Means for the Semiconductor Industry

The significance extends far beyond β-Ga₂O₃.

The same integration strategy could accelerate the development of:

• GaN-on-Diamond RF amplifiers • Ultra-wide-bandgap power electronics • AI accelerator thermal platforms • High-power laser systems • Advanced data-center processors

As device power densities continue to increase, thermal management must move closer and closer to the active junction.

DIASEMI's Vision

At DIASEMI, we have long advocated that the future of electronics will be defined not only by advances in semiconductor materials, but by advances in thermal materials.

This breakthrough confirms a fundamental industry trend:

Diamond is no longer just a heatsink. Diamond is becoming part of the device.

Whether through CVD diamond heat spreaders, diamond-copper composite cooling solutions, diamond microchannel architectures, or future semiconductor-on-diamond platforms, DIASEMI is committed to enabling the next generation of high-performance electronics.