The assistance of thin film deposition with low-energy ion bombardment influences their
final properties significantly. Especially, the application of so-called hyperthermal ions (energy
<100 eV) is capable to modify the characteristics of the growing film without generating a large
number of irradiation induced defects. The nitrogen ion beam assisted molecular beam epitaxy
(ion energy <25 eV) is used to deposit GaN thin films on (0001)-oriented 6H-SiC substrates at
700 C. The films are studied in situ by reflection high energy electron diffraction, ex situ by X-ray
diffraction, scanning tunnelling microscopy, and high-resolution transmission electron microscopy.
It is demonstrated that the film growth mode can be controlled by varying the ion to atom ratio,
where 2D films are characterized by a smooth topography, a high crystalline quality, low biaxial
stress, and low defect density. Typical structural defects in the GaN thin films were identified as
basal plane stacking faults, low-angle grain boundaries forming between w-GaN and z-GaN and
twin boundaries. The misfit strain between the GaN thin films and substrates is relieved by the
generation of edge dislocations in the first and second monolayers of GaN thin films and of misfit
interfacial dislocations. It can be demonstrated that the low-energy nitrogen ion assisted molecular
beam epitaxy is a technique to produce thin GaN films of high crystalline quality.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:84595 |
| Date | 06 April 2023 |
| Creators | Rauschenbach, Bernd, Lotynk, Andriy, Neumann, Lena, Poppitz, David, Gerlach, Jürgen W. |
| Publisher | MDPI |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1996-1944, 690 |
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