Boron Nitride as a Passivation Capping Layer for AlGaN/GaN High Electron Mobility Transistors.

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Physics

Background:

• High-electron mobility transistors (HEMTs) are crucial for high-power applications.
• Passivation layers are essential for device stability and performance.
• AlGaN/GaN HEMTs face challenges with surface states and leakage currents.

Purpose of the Study:

• To investigate the effectiveness of hexagonal boron nitride (h-BN) as a passivation capping layer for AlGaN/GaN HEMTs.
• To analyze the impact of h-BN on the electrical characteristics of HEMTs.
• To evaluate the potential of h-BN for high-power electronic devices.

Main Methods:

• Fabrication of AlGaN/GaN HEMTs with and without h-BN passivation.
• Electrical characterization of the HEMTs, including current-voltage measurements.
• Analysis of gate leakage current, current drainage, extrinsic transconductance, and pulse response.

Main Results:

• HEMTs with h-BN passivation exhibited increased current drainage compared to unpassivated devices.
• A significant 10^3-fold reduction in gate leakage current was observed with h-BN.
• Improved extrinsic transconductance and pulse response due to reduced surface charge-trapping effects.

Conclusions:

• Hexagonal boron nitride (h-BN) serves as an effective passivation capping layer for AlGaN/GaN HEMTs.
• h-BN passivation significantly enhances device performance by mitigating leakage and improving charge dynamics.
• The findings support the use of h-BN in the development of next-generation high-power electronic devices.