Characterization of Al_xGa_1-xN Films Prepared by Plasma- Induced Molecular-Beam Epitaxy on c-Plane Sapphire

Materials Research Society Symposium Proceedings 468, 305 (1997).

Below is the abstract submitted to the meeting, not the abstract of the published paper:
We investigate by conventional and high resolution transmission electron microscopy techniques the structural phenomena that occur during the initial stages of GaN layer growth (metalorganic vapor deposition) on sapphire substrates with different substrate orientations ((0001), i.e., basal plane sapphire, and $\{1\backslash bar\{1\}02\}$, i.e., r-plane sapphire). The r sapphire is characterized by a very anisotropic mismatch, where the mismatch to the GaN layer in the sapphire [1$\backslash bar\{1\}$01] direction is smaller by about a factor of 10 as compared to all other interfacial directions. This peculiar situation is rejected in the population of extended defects such as dislocations and stacking faults. We discuss the observed dislocations lying in this (1$\backslash bar\{1\}$02) or in the basal plane and use TEM micrographs to assess the implications of structure and charge distributions at their cores.

This paper is part of Gallium Nitride and Related Materials II

Contributed by Materials Research Society

last updated Tuesday, May 3, 2005 5:05:24 PM.
© 1998 The Materials Research Society