A Steep-Slope MoS₂/Graphene Dirac-Source Field-Effect Transistor with a Large Drive Current.

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanoelectronics

Background:

• Continuous scaling of transistor feature size is hindered by the subthreshold swing (SS) limit, which restricts supply voltage scaling.
• A new transistor mechanism is required to overcome the thermionic limit of SS while maintaining high drive current.

Purpose of the Study:

• To experimentally demonstrate a novel MoS2/graphene Dirac-source field-effect transistor (DSFET).
• To investigate the performance characteristics of the DSFET, focusing on subthreshold swing and drive current.
• To explore the potential of gate-all-around (GAA) integration for enhanced DSFET performance.

Main Methods:

• Fabrication of a 1.8 nm MoS2 / 0.3 nm graphene heterostructure for DSFET application.
• Characterization of the DSFET's electrical properties, including subthreshold swing and hysteresis.
• Implementation of a gate-all-around (GAA) architecture to further optimize device performance.

Main Results:

• Achieved a steep subthreshold swing (SS) of 37.9 mV/dec at room temperature with minimal hysteresis in the MoS2/graphene DSFET.
• The GAA-integrated MoS2/graphene DSFET demonstrated an even steeper SS of 33.5 mV/dec.
• The GAA DSFET exhibited a 40% increase in normalized drive current to 52.7 μA·μm/μm at VDS = 1 V, with a high current on/off ratio of 10^8.

Conclusions:

• The demonstrated MoS2/graphene DSFET successfully overcomes the SS limit, offering a pathway to overcome supply voltage scaling stagnation.
• The GAA architecture significantly enhances the performance of the DSFET, leading to steeper SS and higher drive currents.
• This technology holds significant potential for the development of next-generation low-power and high-performance electronic devices.