Sub-100 nm channel length graphene transistors

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Graphene exhibits excellent electronic properties, making it a promising material for next-generation electronics.
• Achieving ultra-short channel lengths in graphene transistors is crucial for high-frequency operation.
• Previous fabrication methods often struggled with precise alignment and preserving graphene's intrinsic properties.

Purpose of the Study:

• To report the fabrication of high-performance graphene transistors with sub-100 nm channel lengths.
• To demonstrate a novel self-aligned fabrication approach for graphene transistors.
• To showcase the potential of these transistors for terahertz (THz) electronics.

Main Methods:

• Utilized a self-aligned fabrication process employing highly doped Gallium Nitride (GaN) nanowires as local gates.
• Defined source and drain electrodes through a self-aligned process, with channel length determined by nanowire size.
• Fabricated graphene transistors with channel lengths ranging from 45 nm to 100 nm.

Main Results:

• Achieved scaled transconductance exceeding 2 mS/μm, comparable to leading high electron mobility transistors (HEMTs).
• Demonstrated transit times between 120-220 femtoseconds (fs).
• Projected intrinsic cutoff frequency (f(T)) reaching 700-1400 GHz.

Conclusions:

• The self-aligned fabrication method preserves graphene's high carrier mobility and ensures precise electrode alignment.
• The fabricated graphene transistors exhibit performance suitable for advanced terahertz electronic applications.
• This work highlights the significant potential of graphene-based electronics in the terahertz spectrum.