Work

Unusual reentrant step-flow morphology in low-temperature MBE-grown GaSb(100) enabled by bismuth surfactancy

Year: 2025

Type: article

Abstract: This study reports the discovery of reentrant step-flow growth behavior in homoepitaxial GaSb(100) films grown via molecular beam epitaxy under bismuth surfactancy. Using ex situ atomic force microscopy, we observe a superposition of short-scale mound and large-scale step-flow morphologies at temperatures significantly below the conventional threshold for step-flow growth. The findings suggest that bismuth surfactant atoms facilitate long-range adatom kinetics, enabling step-flowlike features despite reduced thermal energy. This behavior diverges from traditional epitaxial growth models and aligns with previously reported reentrant phenomena in other material systems. The implications for surface morphology control and device fabrication are discussed, highlighting the role of surfactants in enabling nonequilibrium growth pathways.

Source: Journal of Vacuum Science & Technology A Vacuum Surfaces and Films

DOI: 10.1116/6.0004990

Authors: T. Pan Menasuta, John H. McElearney, Thomas E. Vandervelde

Institution: Tufts University

Language: English

Topic: Semiconductor materials and interfaces

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Science Foundation, Tufts University, Office of Naval Research

Awards: G1396866847, G2857379915, Composite Avalanche Nanoantenna Room-Temperature Infrared Photodetectors (CANTRIP)