Premium
Interaction between surface structures and threading dislocations during epitaxial diamond growth
Author(s) -
Mayr Michael,
Fischer Martin,
Klein Oliver,
Gsell Stefan,
Schreck Matthias
Publication year - 2015
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201532243
Subject(s) - dislocation , materials science , condensed matter physics , epitaxy , crystallography , anisotropy , diamond , transmission electron microscopy , geometry , optics , composite material , nanotechnology , chemistry , physics , mathematics , layer (electronics)
Threading dislocations in off‐axis grown heteroepitaxial diamond films have been visualized by preferential etching of the surface. The lateral distributions of the etch pits display characteristic inhomogeneities. Patterns with fourfold symmetry consisting of a cell structure with dislocation poor cores and dislocation rich walls aligned along [100] and [010] appear on (001) samples with off‐axis tilt toward [110]. These patterns which developed after extended growth to a thickness of 1.5 mm are mainly attributed to intrinsic anisotropies in the mutual interaction between neighboring dislocations via their stress fields. In contrast, growth on (001) surfaces with off‐axis direction toward [100] yielded patterns with twofold symmetry. Here, the etch pits are aligned exclusively along the [100] off‐axis direction which is attributed to the additional impact of the local surface inclination on the dislocations, resulting in an effective lateral movement during growth. Dislocation tilting in the local step‐flow direction away from the crystallographic [001] axis, which provides a reasonable mechanism explaining the lateral movement, is confirmed by transmission electron microscopy. Homoepitaxial growth experiments on (001) surfaces 8° off toward [100] reveal etch pit patterns around “V” shaped microstructures that suggest a similar interpretation in terms of an effective lateral movement of dislocations induced by high local surface inclination.