Surface chemistry models for GaAs epitaxial growth and hydride cracking using reacting flow simulations

TL;DR

This paper develops and validates detailed surface chemistry and cracking models for GaAs HVPE growth, enabling accurate simulation of high-speed epitaxial processes and improving understanding of growth kinetics and transport phenomena.

Contribution

It introduces new kinetic and cracking models integrated into CFD simulations, accurately reproducing experimental GaAs growth data and addressing ultra-fast growth rates.

Findings

Models successfully match experimental growth measurements.

Enhanced understanding of hydride cracking and surface reactions.

Simulation supports optimization of high-speed epitaxial growth.

Abstract

Hydride Vapor Phase Epitaxy (HVPE) is a promising technology that can aid in the cost reduction of III-V materials and devices manufacturing, particularly high-efficiency solar cells for space and terrestrial applications. However, recent demonstrations of ultra fast growth rates ($\sim$ 500 $\mu$m/h) via uncracked hydrides are not well described by present models for the growth. Therefore, it is necessary to understand the kinetics of the growth process and its coupling with transport phenomena, so as to enable fast and uniform epitaxial growth. In this work, we derive a kinetic model using experimental data and integrate it into a computational fluid dynamics simulation of an HVPE growth reactor. We also modify an existing hydride cracking model that we validate against numerical simulations and experimental data. We show that the developed growth model and the improved cracking model are able to reproduce experimental growth measurements of \ce{GaAs} in an existing HVPE system.