Improving interfacial thermal conductivity by constructing covalent bond between Ga₂O₃ and SiC.

Area of Science:

• Materials Science
• Semiconductor Physics
• Thermal Management

Background:

• Gallium oxide (Ga₂O₃) is a promising ultra-wide bandgap semiconductor for advanced electronics.
• Low intrinsic thermal conductivity of Ga₂O₃ leads to self-heating issues, limiting device performance.
• Integrating Ga₂O₃ with high thermal conductivity substrates like SiC is hindered by weak interfacial bonding and high thermal resistance.

Purpose of the Study:

• To address the thermal management challenges in Gallium oxide (Ga₂O₃) electronics.
• To enhance heat dissipation by improving the thermal conductivity of Ga₂O₃/SiC heterostructures.
• To investigate the effect of engineered interfacial bonding on phonon transport and device self-heating.

Main Methods:

• Fabrication of Ga₂O₃/SiC heterostructures with an engineered interlayer.
• Characterization of interfacial bonding and structural compatibility.
• Measurement of interface thermal conductivity using advanced thermometry techniques.
• Infrared thermography to assess self-heating mitigation under high power densities.

Main Results:

• Successful construction of strong covalent bonds at the Ga₂O₃/SiC interface via an engineered interlayer.
• Achieved a record interface thermal conductivity of 162 MW/m²·K for Ga₂O₃ heterostructures.
• Demonstrated a significant temperature reduction of up to 29°C in bonded devices, mitigating self-heating.

Conclusions:

• Engineered interfacial bonding provides a practical and effective route for enhancing thermal management in Ga₂O₃ electronics.
• Strong covalent bonding promotes efficient phonon transport across heterojunctions, overcoming thermal bottlenecks.
• The developed approach is extendable to other wide-bandgap semiconductors facing thermal limitations.