2D fin field-effect transistors integrated with epitaxial high-k gate oxide

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Integrating 2D semiconductors and high-k gate oxides into 3D vertical architectures is crucial for ultrascaled transistors but faces significant challenges.
• Existing methods struggle to achieve precise integration and control over the critical dimensions required for next-generation devices.

Purpose of the Study:

• To report the epitaxial synthesis of novel 3D vertical architectures using 2D semiconductor fins and high-k gate oxides.
• To demonstrate the fabrication and characterization of these structures for advanced transistor applications.

Main Methods:

• Epitaxial synthesis of vertically aligned arrays of 2D fin-oxide heterostructures, specifically integrating Bi2O2Se (2D semiconductor) and Bi2SeO5 (high-k gate oxide).
• Achieved atomically flat interfaces and ultrathin fin thicknesses down to one unit cell (1.2 nm).
• Fabricated 2D fin field-effect transistors (FinFETs) based on the synthesized heterostructures.

Main Results:

• Demonstrated wafer-scale, site-specific, and high-density growth of mono-oriented arrays.
• Achieved high electron mobility (μ) up to 270 cm² V⁻¹ s⁻¹.
• Reported ultralow off-state current (I_OFF) ~1 pA μm⁻¹, high on/off current ratios (I_ON/I_OFF) up to 10⁸, and high on-state current (I_ON) up to 830 μA μm⁻¹ at 400 nm channel length.
• Performance metrics meet the low-power specifications projected by the International Roadmap for Devices and Systems (IRDS).

Conclusions:

• The developed 2D fin-oxide epitaxial heterostructures represent a new class of 3D architecture.
• These findings open new avenues for the further extension of Moore's Law through ultrascaled transistor development.
• The precise integration of 2D materials and high-k dielectrics in vertical arrays is a viable strategy for future electronic devices.