Characterization of Growth Defects in GaN Layers withX-ray Microbeam
|Rozaliya I. Barabash 1,2, C Roder 3, G E. Ice 1, Sven Einfeldt 3, S. Figge 3, Detlef Hommel 3, R. F. Davis 4|
1. Oak Ridge National Laboratory (ORNL), One bethel Valley Road, Oak Ridge, TN 37932, United States
The spatially resolved distribution of strain, misfit and threading dislocations, and crystallographic orientation in uncoalesced GaN layers grown on Si(111) by maskless cantilever epitaxy or by pendeo epitaxy on SiC was studied by white beam Laue x-ray microdiffraction, scanning electron and orientation imaging microscopy. Tilt boundaries formed at the column/wing interface depending on the growth conditions. A depth dependent deviatoric strain gradient is found in the GaN. Density of misfit dislocations as well as their arrangement within different dislocation arrays was quantified. Two different kinds of tilt (parallel and perpendicular to the stripe direction) manifested themselves by mutually orthogonal displacement of the (0006)GaN Laue spot relative to the Si (444) Laue spot. Origin of tilts is discussed with respect to the miscut of the Si(111) surface and misfit dislocations formed at the interface.
Presentation: Oral at E-MRS Fall Meeting 2006, Symposium F, by Rozaliya I. Barabash
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-23 15:12 Revised: 2009-06-07 00:44