Dislocation Revelation in Highly Doped N-Type 4H-SiC by Molten KOH Etching with Na2O2 Additive

Yong Zhao Yao; Yukari Ishikawa; Yoshihiro Sugawara; Hiroaki Saitoh; Katsunori Danno; Hiroshi Suzuki; Yoichiro Kawai; Noriyoshi Shibata

doi:10.4028/www.scientific.net/MSF.679-680.290

Paper Titles

Electrical Activity of Structural Defects in 3C-SiC
p.273

Efficient Image Segmentation for Detection of Dislocations in High Resolution Light Microscope Images of SiC Wafers
p.277

Propagation of Stacking Faults in 3C-SiC
p.282

Etch Pits on 4H-SiC Surface Produced by ClF₃ Gas
p.286

Dislocation Revelation in Highly Doped N-Type 4H-SiC by Molten KOH Etching with Na₂O₂ Additive
p.290

Dislocation Analysis in Highly Doped n-Type 4H-SiC by Using Electron Beam Induced Current and KOH+Na₂O₂ Etching
p.294

New Separation Method of Threading Dislocations in 4H-SiC Epitaxial Layer by Molten KOH Etching
p.298

Impact of Carrier Lifetimes on Non-Destructive Mapping of Dislocations in 4H-SiC Epilayers
p.302

Correlation between Thermal Stress and Formation of Interfacial Dislocations during 4H-SiC Epitaxy and Thermal Annealing
p.306

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Dislocation Revelation in Highly Doped N-Type 4H-SiC by Molten KOH Etching with Na₂O₂ Additive

Abstract:

We have proposed a new wet etching recipe using molten KOH and Na2O2 as the etchant (“KN etching”) for dislocation revelation in highly doped n-type 4H-SiC (n+-4H-SiC). Threading screw dislocations (TSDs) and threading edge dislocations (TEDs) have been clearly revealed as hexagonal etch pits differing in pit sizes, and basal plane dislocations (BPDs) as seashell-shaped pits. This new etching recipe has provided a solution to the problem that conventional KOH etching is not effective for dislocation identification in 4H-SiC if the electron concentration is high (>mid-1018 cm-3). We have investigated the effect of SiC off-cut angle on KN etching and it has been shown that the “KN etching” is applicable for the n+-SiC substrate with off-angle from 0o to 8o.