Graphene-Contacted Ultrashort Channel Monolayer MoS₂ Transistors

Area of Science:

• Materials Science
• Nanotechnology
• Electronics Engineering

Background:

• Two-dimensional (2D) semiconductors offer potential for advanced transistors due to inherent immunity to short-channel effects (SCEs).
• Contacting ultrathin 2D materials like monolayer molybdenum disulfide (MoS₂) at the nanoscale remains a significant fabrication challenge.
• Achieving reliable and high-performance field-effect transistors (FETs) with minimal channel lengths is crucial for next-generation electronics.

Purpose of the Study:

• To develop a novel technique for fabricating graphene electrodes suitable for contacting monolayer MoS₂.
• To investigate the performance of ultrashort channel MoS₂ FETs with these novel graphene contacts.
• To demonstrate the feasibility of creating highly scaled 2D material-based electronic devices.

Main Methods:

• A grain boundary widening technique was employed to engineer graphene electrodes.
• Monolayer MoS₂ was used as the channel material in field-effect transistors (FETs).
• Fabrication focused on achieving channel lengths down to approximately 4 nanometers.

Main Results:

• Reliable fabrication of ultrashort channel MoS₂ FETs with channel lengths down to ≈4 nm was achieved.
• The fabricated FETs exhibited superior performance characteristics.
• Nearly Ohmic contacts were realized, and excellent immunity to short-channel effects (SCEs) was observed.

Conclusions:

• The developed grain boundary widening technique provides a facile and effective route for fabricating graphene contacts for 2D materials.
• Ultrashort channel MoS₂ FETs with graphene electrodes demonstrate promising performance for scaled electronics.
• This approach facilitates the development of various 2D material-based devices for future ultrascaled electronic applications.