High-Mobility GaSb Nanostructures Cointegrated with InAs on Si

Area of Science:

• Semiconductor Science and Technology
• Materials Science
• Nanotechnology

Background:

• Gallium antimonide (GaSb) nanostructures on silicon are crucial for p-type transistors and mid-infrared photodetectors.
• Integrating III-V materials with silicon is key for next-generation semiconductor devices.

Purpose of the Study:

• To investigate the metalorganic chemical vapor deposition (MOCVD) of GaSb nanostructures on silicon-on-insulator (SOI) wafers.
• To characterize the properties and optimize the growth of GaSb nanostructures for electronic applications.
• To demonstrate the co-integration of GaSb and Indium Arsenide (InAs) on silicon.

Main Methods:

• Template-assisted selective epitaxy using MOCVD.
• Morphological characterization of GaSb nanostructures.
• Investigation of growth parameters influencing GaSb growth rate.
• Hall/van der Pauw measurements for electrical characterization.
• Demonstration of co-integration with InAs nanostructures.

Main Results:

• Achieved GaSb nanostructures with critical dimensions down to 20 nm with high morphological control.
• Identified GaSb growth rate governed by Sb surface layer desorption, independent of material transport.
• Observed zinc-blende crystal structure with low rotational twin defects.
• Measured high hole mobility of 760 cm²/ (V s) in 20 nm-thick GaSb nanostructures.
• Successfully demonstrated co-integration of GaSb and InAs nanostructures on Si.

Conclusions:

• GaSb nanostructures grown on Si exhibit excellent crystal quality and high hole mobility, comparable to bulk GaSb.
• The developed MOCVD process allows precise control over nanostructure dimensions and crystal structure.
• Co-integration of GaSb and InAs on Si is feasible, enabling advanced complementary III-V MOSFET technology.