Cathodoluminescence (CL) and electron-beam-induced current (EBIC) are versatile techniques to characterize semiconductor materials and devices. In this talk, we review our achievement on the study of widegap semiconductors, GaN and SiC.
The major defects in GaN are dislocations. GaN wafers on sapphire include dislocations of 109 to 107 cm-2 due to lattice mismatch. Fig. 1 shows the secondary electron (SE) and CL images of GaN wafer with different thickness. Such dislocations may agglomerate and form the hexagonal pits of micrometer size. These defects are detrimental for the device performance. Homoepitaxial GaN wafer take over the dislocations of 106 cm-2 from the seeds. We have performed CL study to distinguish dislocation characters and to clarify the effect of dislocations.
The major defects in SiC are threading screw dislocations (TSD) and stacking faults (SF). TSD act as the killer defects due to the surface roughness at the dislocation core region. SF may be generated and expanded due to e-beam irradiation. EBIC is very effective to characterize these defects in SiC. The e-beam enhanced defect generation of SF (Fig.2) will be reviewed.
At the end, we demonstrate 3D spectra imaging of CL, which is very promising to analyze the details of extended defects.
This work was supported from “GaN project”, Study of Future Semiconductors for Sustainable Society in MEXT, Japan.
Figures:
Fig. 1. CL and SE (Inset) images of GaN with different thickness
Fig. 2. EBIC images of a expanding stacking fault (white triangle) in SiC
To cite this abstract:
Takashi Sekiguchi; Cathodoluminescence and EBIC study of widegap semiconductors and devices. The 16th European Microscopy Congress, Lyon, France. https://emc-proceedings.com/abstract/cathodoluminescence-and-ebic-study-of-widegap-semiconductors-and-devices/. Accessed: December 3, 2023« Back to The 16th European Microscopy Congress 2016
EMC Abstracts - https://emc-proceedings.com/abstract/cathodoluminescence-and-ebic-study-of-widegap-semiconductors-and-devices/