Two-Dimensional ZrS₂ and HfS₂ for Making Sub-10 nm High-Performance P-Type Transistors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Device Physics

Background:

• Two-dimensional (2D) transition metal dichalcogenides (TMDCs) are promising for sub-10 nm field-effect transistors (FETs).
• Existing 2D P-type devices exhibit inferior performance compared to N-type devices, hindering complementary metal-oxide-semiconductor (CMOS) development.
• There is a critical need for advanced channel materials to improve P-type FET performance.

Purpose of the Study:

• To investigate the potential of 2D ZrS2 and HfS2 as high-performance P-type MOSFET channel materials.
• To evaluate their electronic properties and device performance using first-principles simulations.
• To demonstrate their suitability for future sub-10 nm integrated circuits.

Main Methods:

• First-principles quantum transport simulations were employed.
• Electronic band structures and carrier effective masses were calculated.
• Performance metrics such as on-state current (Ion) and energy delay product were simulated for scaled devices.

Main Results:

• ZrS2 and HfS2 exhibit continuous in-plane p-orbitals at the valence band edge, resulting in a small hole effective mass (0.24 m0).
• Simulated 10 nm gate length P-type MOSFETs using ZrS2 and HfS2 achieved high on-state currents (Ion) of 2000 μA/μm.
• Even at 5 nm gate length, Ion remained high (∼1500 μA/μm) with competitive energy delay products.

Conclusions:

• 2D ZrS2 and HfS2 are identified as highly competitive channel materials for next-generation P-type FETs.
• Their superior performance surpasses existing 2D materials like MoS2 and WSe2 for scaled P-type devices.
• These findings pave the way for developing high-performance sub-10 nm CMOS integrated circuits.