Regaining a Spatial Dimension: Mechanically Transferrable Two-Dimensional InAs Nanofins Grown by Selective Area...

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Bottom-up epitaxial growth offers benefits for semiconductor nanostructures.
• Existing nanostructures like nanowires lack sufficient spatial dimensions for complex device designs.
• Indium arsenide (InAs) is a promising material for high-mobility electronic devices.

Purpose of the Study:

• To develop a method for growing rectangular InAs nanofins with controlled dimensions.
• To enable the fabrication of InAs nanofin-based devices for electrical characterization.
• To explore the potential of InAs nanofins for future quantum information applications.

Main Methods:

• Dielectric-templated selective-area epitaxy for controlled nanofin growth.
• Transfer of freestanding nanofins onto a separate substrate for device fabrication.
• Fabrication of devices with multiple contacts, global back-gates, and local top-gates.

Main Results:

• Achieved deterministic control over InAs nanofin length, width, and height.
• Measured 3D electron densities of 2.5-5 × 10^17 cm^-3 and surface accumulation layer densities of 3-6 × 10^12 cm^-2.
• Obtained high Hall mobilities (up to 1200 cm^2/(V s)) and field-effect mobilities (up to 4400 cm^2/(V s)).
• Observed quantum interference effects at temperatures up to 20 K.

Conclusions:

• The developed method enables the growth of high-quality InAs nanofins suitable for device fabrication.
• InAs nanofins provide enhanced design flexibility compared to nanowires.
• These nanofins demonstrate excellent electrical properties and potential for complex quantum devices.