Double-Gate MoS₂ Field-Effect Transistor with a Multilayer Graphene Floating Gate: A Versatile Device for Logic,...

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Two-dimensional (2D) materials offer low-temperature processing advantages for electronic devices.
• Existing silicon technology has limitations in achieving certain advanced functionalities like substrate body-bias in planar devices or vertical finFETs without body-bias.
• There is a need for versatile electronic components that can complement or surpass silicon-based technologies.

Purpose of the Study:

• To fabricate and characterize a novel double-gate molybdenum disulfide (MoS2) field-effect transistor (FET) integrated with hexagonal boron nitride (h-BN) gate dielectrics and a multi-layer graphene floating gate (FG).
• To demonstrate the device's capability for logic, memory, and synaptic applications.
• To investigate the impact of h-BN thickness on charge retention within the FG for memory applications.

Main Methods:

• Fabrication of a double-gate MoS2 FET device incorporating h-BN gate dielectrics and a multi-layer graphene FG.
• Characterization of the device's performance under various operating conditions.
• Systematic investigation of different h-BN dielectric thicknesses to assess charge retention properties.

Main Results:

• Demonstration of the MoS2 FET as a logic device with an adjustable threshold voltage (VT) controlled by charges stored in the FG.
• Implementation of the device as a digital flash memory with enhanced reliability due to a lower pass-through voltage.
• Successful operation as a synaptic device, achieving symmetric program/erase conductance changes by decoupling tunneling and gate dielectrics.

Conclusions:

• The developed MoS2 FET device exhibits versatility for logic, memory, and synaptic functionalities.
• The device's compatibility with back-end-of-line integration suggests its potential to augment existing silicon technology.
• This 2D material-based device offers a promising pathway for next-generation electronic applications.