Effects of Basal Plane Dislocation Density in 4H-SiC Substrate on Degradation of Body-Diode Forward Voltage

Naoyuki Kawabata; Atsushi Tanaka; Masatoshi Tsujimura; Yoshinori Ueji; Kazuhiko Omote; Hirotaka Yamaguchi; Hirofumi  Matsuhata; Kenji Fukuda

doi:10.4028/www.scientific.net/MSF.858.384

Paper Titles

Post-Growth Micropipe Formation in 4H-SiC
p.367

Observation of Pair Structures of Threading Dislocation and Surface Defect in 4H-SiC Wafer by Mirror Projection Electron Microscopy
p.371

Mapping of Threading Screw Dislocations in 4H n-Type SiC Wafers
p.376

Electrical Properties of Defects in 4H-SiC Investigated by Photo-Induced-Currents Measurements
p.380

Effects of Basal Plane Dislocation Density in 4H-SiC Substrate on Degradation of Body-Diode Forward Voltage
p.384

Dislocations in SiC Revealed by NaOH Vapor Etching and a Comparison with X-Ray Topography Taken with Various g-Vectors
p.389

Dislocation Characterization in 4H-SiC Crystals
p.393

Cross Section and Plan View STEM Analysis on Identical Conversion Point of Basal Plane Dislocation to Threading Edge Dislocation of 4H-SiC
p.397

Characterization of Threading Screw Dislocations of Burgers Vectors with A-Components in 4H-SiC
p.401

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Effects of Basal Plane Dislocation Density in 4H-SiC Substrate on Degradation of Body-Diode Forward Voltage

Abstract:

We investigated the effect of the basal plane dislocation (BPD) density in 4H-silicon carbide (SiC) substrates on the forward voltage (V_sd) degradation of body-diodes. Using reflection X-ray topography, the BPD density was automatically estimated from the substrates prior to fabrication of metal–oxide–semiconductor field-effect transistors (MOSFETs). A strong positive correlation was found between the V_sd shift, which was calculated from the difference before and after forward bias stress at 160 A/cm² for ~500 hours, and the BPD density of the substrate. We show that it is possible to predict V_sd shifts from the BPD densities of SiC substrates prior to the fabrication of MOSFETs. In addition, we examined the origin of stacking faults (SFs) as a result of the application of forward bias stress. We presume that SFs are formed by BPDs converted to threading edge dislocations at the epi/sub interface, as well as by BPDs penetrating into the epitaxial layer.