Research on Single-Event Burnout Reinforcement Structure of SiC MOSFET

Area of Science:

• Semiconductor device physics
• Power electronics
• Radiation effects in electronics

Background:

• 1200 V Silicon Carbide (SiC) MOSFETs are crucial for high-power applications.
• Single-event burnout (SEB) poses a reliability risk due to heavy ion strikes.
• Existing SiC MOSFET designs require improved SEB resistance for harsh environments.

Purpose of the Study:

• To investigate SEB mechanisms in a novel 1200 V SiC MOSFET with split gate and embedded Schottky barrier diode (SBD).
• To develop and evaluate structural reinforcement techniques to enhance SEB resistance.
• To analyze the trade-offs between SEB improvement and device performance.

Main Methods:

• Device simulation using Sentaurus TCAD to model the SG-SBD-MOSFET structure.
• Analysis of single-event effect (SEE) transient currents and electric field distribution under heavy ion irradiation.
• Design and separate/combined evaluation of P+ body contact area expansion and multi-layer N-type interval buffer layer reinforcements.

Main Results:

• SEB threshold voltage increased by 16% with P+ body contact extension alone.
• SEB threshold voltage increased by 29% with the multi-layer N-type interval buffer layer alone.
• Combined reinforcement increased SEB threshold voltage by 33%, with a minor breakdown voltage reduction from 1632.935 V to 1403.135 V.

Conclusions:

• The proposed reinforcement structures effectively enhance SEB resistance in 1200 V SiC MOSFETs.
• The combined approach offers the most significant improvement in SEB threshold voltage.
• The reinforced devices maintain acceptable performance with a reduced voltage margin.