Atomic transistors based on seamless lateral metal-semiconductor junctions with a sub-1-nm transfer length

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Physics

Background:

• Two-dimensional (2D) transistors offer potential for miniaturization, but achieving high-quality, stable edge contacts remains a challenge.
• Existing metal-semiconductor junctions (MSJs) in 2D devices often suffer from thermal and chemical instability, hindering reproducible performance.
• The development of robust edge contacts is crucial for advancing 2D electronic devices.

Purpose of the Study:

• To present a scalable synthetic strategy for fabricating low-resistance edge contacts in 2D transistors.
• To utilize a thermally stable 2D metal, platinum telluride (PtTe2), as an epitaxial template for controlled material growth.
• To demonstrate improved device performance through novel PtTe2-MoS2 metal-semiconductor junctions.

Main Methods:

• Fabrication of edge-to-edge connected metal-semiconductor junctions (MSJs) using PtTe2 as a template.
• Epitaxial growth of monolayer molybdenum disulfide (MoS2) laterally onto PtTe2.
• Characterization of the PtTe2-MoS2 interface and assessment of electrical properties, including contact resistivity and Schottky barrier height.
• Utilizing conventional lithography for position-selected growth of PtTe2-MoS2 MSJ arrays.

Main Results:

• Achieved low-resistance edge contacts to 2D atomic transistors using a PtTe2-MoS2 metal-semiconductor junction.
• The PtTe2 template enabled the lateral growth of MoS2, forming a seamless atomic interface.
• Synthesized lateral heterojunctions exhibited reduced Schottky barrier dimensions and enhanced carrier injection compared to vertical contacts.
• Demonstrated wafer-scale fabrication of PtTe2-MoS2 MSJ arrays with high processability, low contact resistivity, and ultrashort transfer length.

Conclusions:

• The developed scalable synthetic strategy enables the reproducible fabrication of high-quality, low-resistance edge contacts for 2D transistors.
• The use of thermally stable PtTe2 as an epitaxial template is key to achieving seamless atomic interfaces and improved device performance.
• This approach facilitates the design of advanced 2D electronic devices with enhanced processability and superior electrical characteristics.