Toward defect-free semi-polar GaN templates on pre-structured sapphire

Growth and Coalescence Studies of (112̄2) Oriented GaN on Pre-Structured Sapphire Substrates Using Marker Layers

In this article, the growth and coalescence of semipolar (112̄2) oriented GaN layers, deposited on pre-structured r-plane sapphire substrates, is studied with the help of Si-doped marker layers. It has been found to be very important to adjust the shape of the initial GaN stripes by varying the growth temperature to obtain not only a smooth surface, but also a low density of basal plane stacking...

Structural characterization of non-polar (112 0) and semi-polar (1126) GaN films grown on r-plane sapphire

Thick GaN films, with (1120) or (1126) planes parallel to the r-plane of sapphire, were grown by molecular beam epitaxy using AlN or GaN buffer layers. Characterization by transmission electron microscopy revealed a high density of basal-plane stacking faults (BSFs) in the (1120) non-polar GaN (a-GaN) films. {1120} and {1010} prismatic-plane and {1102} pyramidal-plane stacking faults (SFs) doma...

Low defect large area semi-polar (112) GaN grown on patterned (113) silicon

We report on the growth of semi-polar GaN (112̄2) templates on patterned Si (113) substrates. Trenches were etched in Si (113) using KOH to expose Si {111} sidewalls. Subsequently an AlN layer to prevent meltback etching, an AlGaN layer for stress management, and finally two GaN layers were deposited. Total thicknesses up to 5 m were realised without cracks in the layer. Transmission electron mi...

MOVPE of InN films on GaN templates grown on sapphire and silicon(111) substrates

Growth Investigations of Nitrogen-Polar GaN Nucleation Layer Templates

This study aims at achieving highly crystalline and smooth Nitrogen-polar (N-polar) GaN layers deposited on c-plane sapphire by metal organic vapor phase epitaxy (MOVPE). The influence of nitridation, temperature and V/III ratio on the polarity, quality and coalescence of GaN is systematically investigated. It was observed that the initial nitridation of sapphire before GaN growth is critical f...