Termination of hollow core nanopipes in GaN by an AlN interlayer

Publication date: 1 December 2016
Source:Journal of Crystal Growth, Volume 455
Author(s): O. Contreras, F. Ruiz-Zepeda, M. Avalos-Borja, A. Dadgar, A. Krost
Nanopipes associated to screw dislocations are studied by transmission electron microscopy in Si-doped GaN films grown on silicon substrates. The observations revealed that dislocations had an empty core and that an AlN interlayer is suited to block their propagation. The termination mechanism is discussed in terms of strain and kinetic growth factors, which may affect the creation and propagation of nanopipes. According to the observations, it is proposed that either step pinning or lateral overgrowth occurring at the proximity of the defect assists in capping the nanopipe.