Interfacial Engineering toward Ultralow Thermal Boundary Resistance at Metal-Semiconductor Contacts

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Scaling down semiconductor devices increases heat dissipation challenges.
• Thermal boundary resistance (TBR) at metal-semiconductor interfaces is a critical bottleneck.
• Heat concentration in Gallium Nitride (GaN) devices under gate contacts is a significant issue.

Purpose of the Study:

• To explore and address heat transport across metal-semiconductor junctions.
• To develop an interfacial engineering strategy for reducing TBR in GaN devices.
• To achieve record-low TBR values between metals and GaN.

Main Methods:

• Utilized an ultrathin titanium (Ti) interlayer for interfacial engineering.
• Investigated phonon coupling and transmission across the engineered interface.
• Measured TBR values between diverse metals and GaN with the Ti interlayer.

Main Results:

• Achieved record-low TBR values of 3.5-4.6 m²K/GW between metals and GaN.
• The 3 nm-thick Ti interlayer facilitated elastic phonon coupling via acoustic impedance matching.
• Strong interfacial bonding and suppressed interfacial disorder enhanced phonon transmission.

Conclusions:

• An effective interfacial engineering strategy using ultrathin interlayers was established.
• This approach provides a scalable and universal framework for thermal management in next-generation electronics.
• The study offers solutions for heat dissipation challenges in advanced semiconductor devices.