Field-plate engineering for high breakdown voltage β-Ga₂O₃ nanolayer field-effect transistors

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Nanoelectronic devices face limitations due to narrow voltage swings.
• Beta-gallium oxide (β-Ga₂O₃) possesses a high breakdown field (approx. 8 MV cm^-1), making it promising for next-generation power devices.
• Engineering electric field distribution is crucial for enhancing device performance.

Purpose of the Study:

• To introduce a field-modulating plate into a β-Ga₂O₃ nano-field-effect transistor (nanoFET).
• To engineer electric field distribution and improve breakdown voltage.
• To demonstrate the potential of β-Ga₂O₃ nanoFETs for advanced power electronics.

Main Methods:

• Fabrication of β-Ga₂O₃ nanoFETs using mechanical exfoliation from single-crystal substrates.
• Integration of a field-modulating plate into the nanoFET structure.
• Device simulation to optimize the field-modulating plate layout for electric field distribution.
• Characterization of electrical properties, including breakdown voltage and switching characteristics.

Main Results:

• Achieved an off-state three-terminal breakdown voltage of 314 V.
• Field-plated β-Ga₂O₃ nanoFETs exhibited n-type behavior with high output current saturation.
• Demonstrated excellent switching characteristics: threshold voltage of -3.8 V, subthreshold swing of 101.3 mV dec^-1, and an on/off ratio > 10⁷.

Conclusions:

• The integration of a field-modulating plate significantly enhances the breakdown voltage of β-Ga₂O₃ nanoFETs.
• These high-performance nanoFETs show potential for downsizing power electronic devices.
• The developed technology could lead to more economical and efficient power systems.