Controlled Layer-by-Layer Oxidation of MoTe₂ via O₃ Exposure

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Integrating transition metal dichalcogenides (TMDs) into complementary metal-oxide-semiconductor (CMOS) logic circuits is challenging due to difficulties in growing uniform oxides of controlled thickness.
• Atomically thin TMDs require precise surface functionalization for advanced electronic applications.

Purpose of the Study:

• To develop a controllable method for growing uniform oxide films on atomically thin molybdenum ditelluride (MoTe2).
• To explore the potential of these oxide films in metal-oxide-semiconductor (MOS) transistors.

Main Methods:

• Layer-by-layer oxidation of MoTe2 flakes using ozone (O3) exposure.
• Tuning the thickness of the molybdenum oxide (MoO_x) film by controlling O3 exposure time.
• Characterizing the transport properties of MoO_x-covered MoTe2.

Main Results:

• Achieved atomic-level accuracy in tuning MoO_x film thickness on MoTe2.
• Demonstrated that MoO_x-covered MoTe2 exhibits hole-dominated transport behavior.
• Established a simple and effective strategy for homogeneous surface oxide film growth.

Conclusions:

• The layer-by-layer ozone oxidation offers a precise method for fabricating oxide films on MoTe2.
• This technique is promising for applications in MOS transistors, including surface passivation and dielectric layers.
• The controlled oxide growth facilitates the integration of TMDs into advanced semiconductor devices.