Characteristics of 3D-Integrated GaN Power Module Under Multi Heat Source Coupling

Area of Science:

• Power Electronics
• Semiconductor Devices
• Thermal Management

Background:

• 3D-integrated Gallium Nitride (GaN) power modules offer reduced parasitics and enhanced performance.
• Operating GaN power chips generate heat, leading to mutual thermal coupling.
• This coupling can negatively affect GaN power chip characteristics and overall system reliability.

Purpose of the Study:

• To investigate the impact of thermal coupling in 3D-integrated GaN power modules on GaN power chip characteristics.
• To quantify the performance degradation caused by heat generated from adjacent chips.

Main Methods:

• Characterization of GaN power chips before and after exposure to thermal stress from other chips.
• Application of specific gate-source (VGS) and drain-source (VDS) voltages (3 V/1 V) for 60 seconds to induce thermal coupling.
• Analysis of threshold voltage shift, response speed, on-state current, and leakage current.

Main Results:

• Thermal coupling causes a rightward shift in threshold voltage (up to 0.26 V).
• Device response time increased significantly (up to 217 μs), and on-state current decreased (by 1.7 A).
• Off-state leakage current increased dramatically (over 80 times), with effects dependent on chip proximity and position.

Conclusions:

• Thermal coupling in 3D-integrated GaN power modules adversely affects GaN power chip performance.
• Performance degradation is more severe with closer chip proximity and for chips nearer the bottom substrate.
• Understanding and mitigating thermal coupling is crucial for reliable 3D-integrated GaN power systems.