What question did this study set out to answer?

The research aims to enhance the crystal quality of GaN films grown on sapphire substrates by optimizing nucleation methods.

March 12, 2026Open Access

GaN catalyzed nucleation of thin low threading dislocation GaN on sapphire

Key Points

The research aims to enhance the crystal quality of GaN films grown on sapphire substrates by optimizing nucleation methods.
Utilized a GaN surface for improved nucleation during growth on sapphire.
Analyzed crystal quality using x-ray diffraction for both symmetric and asymmetric reflections.
Characterized surface roughness with atomic force microscopy.
Achieved narrower x-ray diffraction peaks, indicating improved crystal quality.
Developed a GaN buffer layer approximately 1 μm thick with comparable quality to a thicker (3 μm) layer.
Obtained low roughness in device-grade epitaxial GaN layers as thin as 0.6 μm.

Abstract

Because of the presence of a GaN surface during GaN nucleation and growth on sapphire substrates, a substantial improvement in crystal quality, as observed by narrowing of the x-ray diffraction rocking curve peaks corresponding to symmetric (0002) and asymmetric (10–12) reflections, was observed. Using this method, a GaN buffer layer with a thickness of about 1 μm and a crystal quality comparable to that of the more commonly used thicker, about 3 μm, GaN buffer layer on sapphire was obtained. In addition, deposition of GaN layers as thin as 0.6 μm on sapphire yielded a device-grade epitaxial surface exhibiting low roughness, as confirmed by atomic force microscopy.

GaN catalyzed nucleation of thin low threading dislocation GaN on sapphire

Key Points

Abstract

Cite This Study