Characterization of crystallographic defects in homoepitaxial diamond films by synchrotron X-ray topography and cathodoluminescence

Crystallographic defects in a p-type homoepitaxial diamond film grown by microwave plasma-assisted chemical vapor deposition on a synthetic high-pressure high-temperature type-Ib (001) substrate were characterized by synchrotron radiation X-ray diffraction topography (XRT) and cathodoluminescence (CL). CL mapping indicated typical luminescent spots corresponding to the band-A emission around 420 nm. The band-A spots correspond to the spots observed by XRT for both diffraction vectors g = [044] and [404], and are considered to be mixed dislocations with a dislocation direction t = [001]. Typical dislocations in the film, such as edge and perfect 60° dislocations were determined by utilizing the relationship between the diffraction vector g, Burgers vector b, and the dislocation line vector t.

Research Highlights
► High density of dislocations (103 /cm2) are observed on homoepitaxially grown diamond film with low roughness surface.
► Typical dislocations such as edge, 60o and mixed dislocations are observed by synchrotron radiation X-ray topography and cathode luminescence.
► Band-A luminescence was confirmed at the position of mixed dislocations.