A Novel GaN Metal-Insulator-Semiconductor High Electron Mobility Transistor Featuring Vertical Gate Structure

Area of Science:

• Materials Science
• Semiconductor Physics
• Electrical Engineering

Background:

• Gallium Nitride (GaN)-based High Electron Mobility Transistors (HEMTs) are crucial for power electronics.
• Achieving normally-off operation with high performance in GaN HEMTs remains a challenge.
• Conventional lateral structures face limitations in on-resistance and threshold voltage control.

Purpose of the Study:

• To propose and verify a novel normally-off GaN-based HEMT structure.
• To investigate the impact of transposing gate channel orientation on device performance.
• To reduce on-resistance and improve threshold voltage for enhanced HEMTs.

Main Methods:

• Utilizing Technology Computer-Aided Design (TCAD) simulations for device verification.
• Implementing a novel structure scheme with a short vertical gate channel orientation.
• Comparing the proposed structure against conventional lateral HEMTs.

Main Results:

• The proposed vertical gate structure achieves a high threshold voltage of 3.1 V.
• Demonstrated a high peak transconductance of 213 mS.
• Achieved significantly lower on-resistance of 0.53 mΩ·cm².
• Exhibited improved off-state characteristics due to uniform electric field distribution.

Conclusions:

• The novel vertical gate structure offers a new pathway for high-performance normally-off GaN HEMTs.
• This design overcomes limitations of conventional lateral structures.
• The findings pave the way for more efficient power electronic devices.