Relaxation mechanism of GaP grown on 001 Sisubstrates: influence of defects on the growth of AlGaPlayers on GaP/Si templates

TL;DR

This study investigates how high-temperature annealing causes defects in GaP/Si templates, affecting the quality of subsequent GaP and AlGaP layers grown via MOCVD.

Contribution

It reveals the relaxation mechanism and defect formation in GaP/Si templates during annealing, impacting subsequent epitaxial growth.

Findings

High-temperature annealing induces plastic relaxation in GaP/Si templates.

Annealing leads to micro-twin defects that impair layer quality.

Defects negatively influence the growth of GaP and AlGaP layers.

Abstract

The mechanical stability of commercial GaP/Si templates during thermal an-nealing and subsequent MOCVD growth of GaP and AlGaP is investigated.Although the GaP layer of the template originally presents an excellent surfacemorphology, annealing at high enough temperatures to remove the native oxideprior to growth leads to plastic relaxation, accompanied by a variety of defects,including a dense grid of micro-twins. These micro-twins detrimentally affectGaP and AlGaP layers grown subsequently on the template.