Selective-Area Growth of Vertical InGaAs/GaSb Core-Shell Nanowires on Silicon and Dual Switching Properties.

Area of Science:

• Semiconductor Nanostructures
• Epitaxial Growth
• Quantum Well Structures

Background:

• Antimonide (Sb)-related quantum well epitaxy is well-studied.
• GaSb facet growth in selective-area growth (SAG) and nanostructures remains unexplored due to Sb adatom diffusion and surfactant effects.

Purpose of the Study:

• Investigate GaSb facet growth morphology in SAG using InGaAs nanowires (NWs).
• Characterize the growth processes and control mechanisms for GaSb shell formation.
• Explore the electronic properties and potential applications of InGaAs/GaSb core-shell NWs.

Main Methods:

• Monolithic growth of InGaAs nanowires (NWs) on a Si template.
• Selective-area growth (SAG) of GaSb on InGaAs NWs.
• Characterization of growth morphology and electronic properties.

Main Results:

• Identified four key growth processes in SAG of GaSb on NWs: lateral overgrowth, axial growth, step-flow growth, and Sb adatom desorption.
• Demonstrated control over dominant growth processes via GaSb growth temperature, enabling smooth GaSb shell formation.
• Observed moderate rectifying properties in vertical InGaAs/GaSb core-shell NW diodes.
• Exhibited dual-carrier modulation (p-channel FET and n-channel TFET modes) in a single transistor architecture.

Conclusions:

• GaSb facet growth in SAG on NWs is controllable by temperature, yielding smooth shells.
• InGaAs/GaSb core-shell NWs show potential for integrated circuits through unique dual-carrier transistor behavior.