High-Gain Graphene Transistors with a Thin AlOx Top-Gate Oxide

Area of Science:

• Solid State Physics
• Materials Science
• Electrical Engineering

Background:

• Transistor high-frequency performance is critical for electronics.
• Key metrics include maximum oscillation frequency (f_max), cutoff frequency (f_T), and voltage gain (A_v).
• Existing graphene field-effect transistors (GFETs) have limitations in achieving optimal performance.

Purpose of the Study:

• To demonstrate high-performance GFETs using a thin AlOx gate dielectric.
• To surpass the state-of-the-art in GFET speed and gain figures of merit.
• To explore the potential of these GFETs in practical electronic applications.

Main Methods:

• Fabrication of GFETs with a thin AlOx gate dielectric.
• S-parameter measurements to assess high-frequency performance.
• DC characterization under ambient conditions.

Main Results:

• Achieved f_max/f_T > 3, A_v > 30 dB, and S₂₁ = 12.5 dB (at 10 MHz).
• Demonstrated good current saturation and transconductance (~600 S/m) in DC characterization.
• Outperformed previous state-of-the-art GFETs.

Conclusions:

• The developed GFETs exhibit excellent high-frequency characteristics.
• These GFETs show significant promise for applications demanding high gain.
• Graphene can be effectively utilized in advanced electronic devices.