Achieving short high-quality gate-all-around structures for horizontal nanowire field-effect transistors

Area of Science:

• Semiconductor device fabrication
• Nanotechnology
• Materials science

Background:

• Traditional nanowire transistor fabrication methods face limitations in controlling gate length.
• Achieving precise gate control is crucial for advanced transistor performance.

Purpose of the Study:

• To introduce a novel fabrication method for gate-all-around (GAA) nanowire field-effect transistors (FETs).
• To overcome limitations in minimal gate length and gate-length control in existing horizontal wrap-gated nanowire transistors.

Main Methods:

• Utilized a resist-trench alignment technique to position single nanowires perpendicular to bottom gates.
• Defined top gates aligned to bottom gates to create GAA structures.
• Employed electron-beam lithography for precise gate-length definition.

Main Results:

• Successfully fabricated devices with independent bottom, top, and GAA structures.
• Demonstrated GAA structures with gate lengths of 300, 200, and 150 nm.
• Achieved subthreshold swings as low as 38 mV/decade at 77 K for a 150 nm gate length.

Conclusions:

• The presented fabrication method offers superior gate-length control compared to wet-etching techniques.
• This approach enables the creation of high-performance GAA nanowire FETs with minimal gate lengths.
• The method is versatile and suitable for fabricating advanced nanoscale electronic devices.