Comparison of the properties of GaN grown on complex Si-based structures

TL;DR

This study compares the structural and optical properties of GaN layers grown on complex silicon-based structures, demonstrating high-quality epitaxial growth suitable for optoelectronic device integration.

Contribution

It provides a detailed analysis of GaN growth on Si(111) SOI and Si/CoSi2/Si(111), highlighting improved crystalline quality and optical properties on Si(111) SOI.

Findings

GaN exhibits highly oriented wurtzite structure on both substrates.

GaN on Si(111) SOI has better crystalline quality than on silicide.

Strong near-bandedge photoluminescence at 368 nm observed.

Abstract

With the aim of investigating the possible integration of opto-electronic devices, epitaxial GaN layers have been grown on Si(111) SOI and on Si/CoSi2/Si(111) using metalorganic chemical vapor deposition. The samples are found to possess a highly oriented wurtzite structure, a uniform thickness and abrupt interfaces. The epitaxial orientation is determined as GaN(0001)//Si(111), GaN[1120]//Si[110] and GaN[1010]//Si[112], and the GaN layer is tensily strained in the direction parallel to the interface. According to Rutherford backscattering/channeling spectrometry and (0002) rocking curves, the crystalline quality of GaN on Si(111) SOI is better than that of GaN on silicide. Room-temperature photoluminescence of GaN/SOI reveals a strong near-bandedge emission at 368 nm (3.37 eV) with an FWHM of 59 meV.