Mechanism Analysis and Multi-Scale Protection Design of GaN HEMT Induced by High-Power Electromagnetic Pulse

Area of Science:

• Materials Science
• Electrical Engineering
• Physics

Background:

• Severe electromagnetic conditions pose significant risks to modern electronic systems.
• Gallium Nitride (GaN) high-electron-mobility transistors (HEMTs) are crucial components in many electronic applications.
• Understanding the damage mechanisms of high-power electromagnetic pulses (EMPs) on GaN HEMTs is vital for reliability.

Purpose of the Study:

• To investigate the detailed damage effects of high-power electromagnetic pulses (EMPs) on GaN HEMTs.
• To elucidate the underlying physical mechanisms causing device damage.
• To propose and validate a multi-scale protection design for GaN HEMTs against high-power electromagnetic interference (EMI).

Main Methods:

• Detailed analysis of internal physical quantity variations within the GaN HEMT during EMP exposure.
• Device structure optimization, focusing on symmetry (Lgd=Lgs) and passivation layers.
• Circuit optimization, evaluating the impact of external resistive components.
• Simulation studies to verify the proposed protection strategies.

Main Results:

• Device damage is primarily caused by thermal accumulation effects, including self-heating, avalanche breakdown, and hot carrier emission.
• Symmetrical device structures (gate-to-drain and gate-to-source distances equal) exhibit a higher damage threshold than asymmetrical ones.
• Appropriate passivation layers enhance breakdown characteristics, improving anti-EMI capability.
• Series resistive components in the source and gate circuits significantly increase the device's EMP withstand capability.

Conclusions:

• The reliability of GaN devices operating in harsh electromagnetic environments can be improved through strategic design.
• Device structure optimization, particularly symmetry and passivation, is key to enhancing EMP resilience.
• Circuit-level protection using series resistors offers an effective method to bolster GaN HEMT immunity against EMPs.