Title
X-ray characterization of physical-vapor-transport-grown bulk AlN single crystals
Date Issued
01 August 2020
Access level
open access
Resource Type
journal article
Author(s)
Wicht T.
Muller S.
Epelbaum B.
Besendorfer S.
Bla U.
Weisser M.
Unruh T.
Meissner E.
Fraunhofer IISB
Publisher(s)
International Union of Crystallography
Abstract
AlN slices from bulk crystals grown under low thermomechanical stress conditions via the physical vapor transport (PVT) method were analyzed by X-ray methods to study the influence of the growth mode on the crystal quality. Defect types and densities were analyzed along axial [0001] as well as lateral growth directions. X-ray diffraction (0110) rocking-curve mappings of representative wafer cuts reveal a low mean FWHM of 13.4arcsec, indicating the generally high crystal quality. The total dislocation density of 2 × 103cm-2 as determined by X-ray topography is low and dislocations are largely threading edge dislocations of b = 1/31120 type. The absence of basal plane dislocations in homogeneous crystal regions void of macroscopic defects can be linked to the low-stress growth conditions. Under the investigated growth conditions this high crystal quality can be maintained both along the axial [0001] direction and within lateral growth directions. Exceptions to this are some locally confined, misoriented grains and defect clusters, most of which are directly inherited from the seed or are formed due to the employed seed fixation technique on the outer periphery of the crystals. Seed-shaping experiments indicate no apparent kinetic limitations for an enhanced lateral expansion rate and the resulting crystal quality, specifically with regard to the growth mode on a-face facets.
Start page
1080
End page
1086
Volume
53
Language
English
OCDE Knowledge area
FÃsica atómica, molecular y quÃmica
Óptica
Subjects
Scopus EID
2-s2.0-85092331690
Source
Journal of Applied Crystallography
ISSN of the container
00218898
Sponsor(s)
Funding text
This work was supported by the Bavarian State Ministry for Economic Affairs and Media, Energy and Technology under the program ELSYS Bayern and the contract Nos. ESB-1604-0002//ESB035/001 and ESB-1809-0021//ESB085/001.
Sources of information:
Directorio de Producción CientÃfica
Scopus