Defect structures in (001) zincblende GaN/3C-SiC nucleation layers

Abstract

The defect structure of zincblende GaN nucleation layers grown by metalorganic vapor-phase epitaxy on 3C-SiC/Si (001) was investigated by high-resolution scanning transmission electron microscopy. Perfect dislocations, partial dislocations, and stacking faults are present in the layers. Perfect dislocations are identified as 60° mixed-type and act as misfit dislocations to relieve the compressive lattice mismatch strain in GaN. Stacking faults are mainly bounded by 30° Shockley partial dislocations and rarely by Lomer-Cottrell partial dislocations, both of which are able to relieve the compressive lattice mismatch strain in the layer. We propose that the stacking faults and their partial dislocations originate from the dissociation of perfect dislocations present in the zincblende GaN layer, and by direct nucleation of partial dislocations loops from the surface. These are the two main mechanisms, which lead to the final defect structure of the zincblende GaN nucleation layers.

AlN Buffer Enhances the Layer Quality of MBE-Grown Cubic GaN on 3C-SiC

“…Therefore, the substrate-epilayer interface needs optimization because defects such as dislocations and stacking faults (SFs) originate here and spread through the bulk layer. 16 One route to circumvent these issues is the introduction of a thin c-AlN buffer layer between the 3C-SiC substrate and the c-GaN epilayer. Conceptually, the c-AlN buffer spatially separates the lattice mismatch and change of ionicity between the substrate and the c-GaN layers: the cubic AlN is virtually lattice matched to the 3C-SiC with a residual lattice mismatch of only 0.3%.…”

“…They are observed as bright lines propagating through the entire GaN layer. 16,39 Two SFs with different inclinations can annihilate when they intersect. This then results in the decrease of the overall defect density.…”

“…Their reduction enhances the crystal quality of heteroepitaxial c-GaN. Therefore, the substrate-epilayer interface needs optimization because defects such as dislocations and stacking faults (SFs) originate here and spread through the bulk layer …”

Overcoming the Miscibility Gap of GaN/InN in MBE Growth of Cubic InxGa1–xN

“…The majority of the stacking faults (SF) in the c-In x Ga 1– x N layer in the [110] direction (Figure a) originate in the c-GaN layer and penetrate the GaN/In x Ga 1– x N interface. Those stacking faults form at the interfaces of 3C-SiC/AlN/GaN and propagate through the entire epitaxial layer if no SF annihilation process occurs. ,− Therefore, reducing the number of SFs in the c-GaN substrate should also decrease the SF concentration in the c-In x Ga 1– x N layer. Apart from the SFs, the HR-HAADF image (Figure b) of c-In x Ga 1– x N shows the expected zincblende structure.…”

High Efficiency Focusing and Vortex Generator Based on Polarization-Insensitive Gallium Nitride Metasurface

“…The simulation results proved the superiority of GaN and are also consistent with the theoretical analyses. Due to the advantages of high power and high bandwidth, the GaN metasurface can be widely applied in industrial communication fields, and it will lead the third-generation semiconductor market [32,33].…”