Dual-Gate p-GaN Gate High Electron Mobility Transistors for Steep Subthreshold Slope

Area of Science:

• Semiconductor Physics
• Materials Science
• Electrical Engineering

Background:

• High-electron-mobility transistors (HEMTs) are critical components in modern electronics.
• Achieving steep subthreshold slopes is essential for low-power device operation.
• Parasitic effects in single-gate devices can lead to abrupt drain current increases.

Purpose of the Study:

• To investigate the performance of a p-GaN gate HEMT with a dual-gate structure.
• To analyze the factors affecting subthreshold slope and drain current.
• To evaluate the switching speed and transient response of the dual-gate device.

Main Methods:

• Fabrication and characterization of p-GaN gate HEMTs with single-gate and dual-gate structures.
• Electrical measurements including subthreshold slope and drain current analysis.
• Temperature-dependent measurements and transient response analysis to determine switching speed.

Main Results:

• A steep subthreshold slope below 120 μV/dec was achieved with the dual-gate p-GaN HEMT.
• Parasitic floating-base bipolar transistor breakdown and hole accumulation were identified as causes for drain current increase in single-gate devices.
• The dual-gate device exhibited stable subthreshold slope at high temperatures, with a switching speed of approximately 10⁻⁵ seconds.

Conclusions:

• The dual-gate structure effectively enhances the subthreshold slope characteristic in p-GaN HEMTs.
• Understanding parasitic effects is crucial for optimizing HEMT performance.
• The dual-gate HEMT demonstrates promising switching speeds for high-frequency applications.