• Liliental-Weber, Z.
• Zakharov, Dn
• Reitmeier, Zj
• Wagner, B.
• Davis, Rf

Abstract

<p>Pendeo-epitaxy has been applied to nonpolar a-plane GaN layers in order to observe if such process will lead to defect reduction in comparison with direct growth on this plane. Uncoalesced and coalesced a-plane GaN layers with thicknesses 2 mu m and 12 mu m, respectively, have been studied by conventional and high resolution electron microscopy. The following structural defects have been observed in pendeo-epitaxial layers: (1) basal stacking faults, (2) threading dislocations, and (3) prismatic stacking faults. A drastic decrease in the density of threading dislocations and stacking faults was observed in 'wing' areas with respect to 'seed' areas. Cross-section images reveal cracks and voids at the areas where two coalesced wings meet each other. High resolution electron microscopy shows that the majority of stacking faults are low-energy planar defects of the types I-1, I-2 and I-3. The I-3 type basal stacking fault, predicted theoretically, was observed experimentally for the first time.</p>

Topics

• density
• crack
• transmission electron microscopy
• dislocation
• void
• stacking fault