Graphene Field-Effect Transistors Employing Different Thin Oxide Films: A Comparative Study.

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Graphene field-effect transistors (GFETs) are promising for high-frequency applications.
• The choice of gate dielectric significantly impacts GFET performance.
• Optimizing dielectric materials is crucial for enhancing microwave response.

Purpose of the Study:

• To compare the microwave response of GFETs using different gate dielectric materials.
• To evaluate aluminum oxide (Al2O3), titanium oxide (TiO2), and hafnium oxide (HfO2) as gate dielectrics.
• To identify the optimal dielectric for superior GFET microwave performance.

Main Methods:

• Fabrication of GFETs with Al2O3, TiO2, and HfO2 gate dielectrics on a single chip.
• Statistical analysis of 24 devices for each dielectric type.
• Direct current and microwave measurements to assess performance.

Main Results:

• GFETs with each dielectric exhibited well-defined performance curves.
• Hafnium oxide (HfO2) demonstrated superior dielectric properties for GFETs.
• GFETs utilizing HfO2 showed enhanced cutoff frequency and maximum oscillation frequency.

Conclusions:

• Hafnium oxide (HfO2) is the optimal dielectric for high-performance microwave GFETs.
• The selection of gate dielectric is critical for tailoring GFET characteristics.
• This research provides valuable insights for the development of advanced graphene-based electronics.