MoS₂-on-AlN Enables High-Performance MoS₂ Field-Effect Transistors through Strain Engineering

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Molybdenum disulfide (MoS2) shows promise for advanced electronic devices.
• High-quality MoS2 film fabrication is crucial for device performance.
• Substrate choice significantly impacts MoS2 film properties and device characteristics.

Purpose of the Study:

• To investigate the influence of different substrates on the performance of MoS2-based field-effect transistors.
• To identify optimal substrate conditions for high-performance MoS2 film synthesis.
• To explore the potential of MoS2 films for microelectronic applications.

Main Methods:

• Large-area MoS2 films were synthesized using atomic layer deposition.
• Top-gate MoS2 field-effect transistor arrays were fabricated on AlN, GaN, sapphire, and SiO2 substrates.
• Device performance, particularly carrier mobility, was analyzed across different substrates.

Main Results:

• Interface defects, stemming from lattice mismatch and substrate roughness, drastically reduce MoS2 mobility.
• Transistors fabricated on AlN substrates exhibited enhanced mobility (10.45 cm2 V-1 s-1) due to minimal lattice mismatch and superior surface quality.
• MoS2 transistors on GaN, sapphire, and SiO2 substrates showed significantly lower mobility.

Conclusions:

• Aluminum nitride (AlN) is identified as a superior substrate for fabricating high-performance, large-area MoS2 films.
• The findings highlight the critical role of substrate selection in mitigating interface defects for improved MoS2 device characteristics.
• This work supports the integration of MoS2-based electronics into advanced microelectronic systems, including digital logic circuits.