Evolution of the surface morphology of GaSb epitaxial layers deposited by molecular beam epitaxy (MBE) on GaAs (100) substrates

TL;DR

This paper investigates how different epitaxial growth methods affect the surface morphology of GaSb layers on GaAs substrates, aiming to optimize buffer layer quality for infrared detector applications.

Contribution

It compares three distinct GaSb epitaxial growth techniques, including a novel method with Be doping, to identify the most effective approach for high-quality buffer layers.

Findings

The third method with Be doping produces superior surface morphology.

The choice of growth method significantly impacts buffer layer quality.

Using GaAs substrates with optimized GaSb buffers is cost-effective for infrared detectors.

Abstract

This study presents a demonstration of the surface morphology behavior of gallium antimonide (GaSb) layers deposited on gallium arsenide (GaAs) (100) substrates using three different methods: metamorphic, interfacial misfit (IMF) matrix, and a method based on a Polish patent application number P.443805. The first two methods are commonly used, while the third differs in the sequence of successive steps and the presence of Be doping at the initial growth stage. By comparing GaSb layers made by these methods for the same growth parameters, the most favorable procedure for forming a GaSb buffer layer is selected. Using GaAs substrates with a GaSb buffer layer is a cheaper alternative to using GaSb substrates in infrared detector structures based on II-type superlattices T2SL, such as InAs/GaSb. The quality of the GaSb buffer layer determines the quality of the subsequent layers that form the entire T2SL and affects factors such as dark current in terms of application