Basal Plane Dislocation Mitigation Using High Temperature Annealing in 4H-SiC Epitaxy

2013 ◽  
Vol 58 (4) ◽  
pp. 325-329
Author(s):  
N. A. Mahadik ◽  
A. Nath ◽  
E. A. Imhoff ◽  
R. E. Stahlbush ◽  
R. Nipoti
Keyword(s):  
High Temperature ◽  
Basal Plane ◽  
High Temperature Annealing ◽  
Basal Plane Dislocation

Annealing Behavior of Electrical Resistivities Perpendicular and Parallel to the Basal Plane of Heavily Nitrogen-Doped 4H-SiC Crystals

2018 ◽  
Vol 924 ◽  
pp. 293-296 ◽  
Author(s):  
Kiyo Okawa ◽  
Yuina Mannen ◽  
Kentaro Shioura ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
...  
Keyword(s):  
High Temperature ◽  
Basal Plane ◽  
Stacking Fault ◽  
High Temperature Annealing ◽  
Annealing Behavior ◽  
Nitrogen Doped ◽  
Electrical Resistivities ◽  
C 30 ◽  
Induced Changes

The annealing behavior of electrical resistivities perpendicular and parallel to the basal plane of heavily nitrogen-doped 4H-SiC crystals was investigated. The temperature dependencies of the resistivities exhibited characteristic behaviors after multiple rounds of high-temperature annealing (1100°C, 30 min). High-temperature annealing induced stacking fault formation to various extents in heavily nitrogen-doped 4H-SiC crystals. Based on these results, we discuss the cause and mechanism of the observed annealing-induced changes in electrical resistivities of the crystals.

Observation of Shrinking and Reformation of Shockley Stacking Faults by PL Mapping

2006 ◽  
Vol 527-529 ◽  
pp. 375-378 ◽  
Author(s):  
Toshiyuki Miyanagi ◽  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
Tomonori Nakamura ◽  
R. Ishii ◽  
...  
Keyword(s):  
High Temperature ◽  
Laser Irradiation ◽  
High Power ◽  
Stacking Faults ◽  
High Temperature Annealing ◽  
High Power Laser ◽  
Power Laser ◽  
Before And After ◽  
Basal Plane Dislocation ◽  
Pl Mapping

We provide evidence of shrinking of Shockley-type stacking faults (SSFs) in the SiC epitaxial layer by high temperature annealing. Photoluminescence (PL) mapping in combination with high-power laser irradiation makes it possible to investigate the formation of SSFs, which lie between a pair of partial dislocations formed by dissociation of a basal plane dislocation (BPD), without fabrication of pin diodes. Using this technique, we investigated the annealing effect on SSFs. Comparing before and after annealing at 600°C for 10 min, it became obvious that high-temperature annealing results in shrinking of the faulted area of the SSFs. The SSFs form into the same features as those before annealing when high-power laser irradiation is performed again on the same area. This result shows that the faulted area of SSFs shrinks by 600°C annealing but the nuclei of SSFs (BPDs) do not disappear.

Conversion of Basal Plane Dislocations to Threading Edge Dislocations by High Temperature Annealing of 4H-SiC Epilayers

2012 ◽  
Vol 1433 ◽  
Author(s):  
Xuan Zhang ◽  
Hidekazu Tsuchida
Keyword(s):  
High Temperature ◽  
Basal Plane ◽  
Image Force ◽  
Line Tension ◽  
Grazing Incidence ◽  
High Temperature Annealing ◽  
X Ray ◽  
Before And After ◽  
Edge Dislocations ◽  
Epilayer Surface

ABSTRACTConversion of basal plane dislocations (BPDs) to threading edge dislocations (TEDs) has been observed in 4H-SiC epilayers by simple high temperature annealing. Grazing incidence reflection synchrotron X-ray topography was used to image the dislocations in the epilayers. By comparing the X-ray topographs before and after annealing, some of the BPDs were confirmed to convert to TEDs from the epilayer surface. The dislocation behaviors during annealing are explained and the mechanism of BPD conversion is discussed. It is argued that the conversion process is realized by constricted BPD segments cross-slipping to the prismatic plane driven by the image force and TED glide on its slip plane driven by the line tension. Certain kinetic processes may assist the formation of constrictions on the BPDs.

Post-Growth Reduction of Basal Plane Dislocations by High Temperature Annealing in 4H-SiC Epilayers

2014 ◽  
Vol 778-780 ◽  
pp. 324-327 ◽  
Author(s):  
Nadeemullah A. Mahadik ◽  
Robert E. Stahlbush ◽  
Anindya Nath ◽  
Marko J. Tadjer ◽  
Eugene A. Imhoff ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Morphology ◽  
Basal Plane ◽  
High Temperature Annealing ◽  
Complete Elimination ◽  
Growth Reduction

Basal Plane Dislocations (BPD) were reduced in 4H-SiC epilayers by high temperature annealing in the range of 1600 °C to 1950 °C using two annealing techniques. Samples annealed at > 1750 °C showed almost complete elimination of BPDs propagating from the substrate. However, surface morphology was degraded for MW annealed samples above 1800 °C, with new BPDs being generated from the surface. A new capping technique was developed along with application of high N2overpressure to preserve the surface morphology and avoid formation of new BPDs.

Bipolar Degradation of 6.5 kV SiC pn-Diodes: Result Prediction by Photoluminescence

2016 ◽  
Vol 858 ◽  
pp. 410-413 ◽  
Author(s):  
Larissa Wehrhahn-Kilian ◽  
Karl Otto Dohnke ◽  
Daniel Kaminzky ◽  
Birgit Kallinger ◽  
Steffen Oppel
Keyword(s):  
High Temperature ◽  
Basal Plane ◽  
Forward Bias ◽  
Crystal Defects ◽  
High Temperature Annealing ◽  
Stress Tests ◽  
Wafer Level ◽  
Electrical Stress ◽  
Implantation Process ◽  
The Stability

The stability of 6.5 kV pn-diodes is dependent on the absence of critical crystal defects, such as basal plane dislocations. In this paper, we present a method to detect these defects on wafer level by utilizing photoluminescence (PL). The PL scan is performed immediately after epitaxy and also after the implantation process steps with subsequent high temperature annealing. The analysis of both scans enables the prediction of devices that will drift due to bipolar degradation, and devices that will exhibit non-drifting behaviour. To validate this PL scanning technique, forward bias electrical stress tests have been performed on the fabricated 6.5 kV pn-diodes.

Analysis of Basal Plane Dislocation Dynamics in 4H-SiC Crystals during High Temperature Treatment

2019 ◽  
Vol 963 ◽  
pp. 268-271
Author(s):  
Balaji Raghothamachar ◽  
Yu Yang ◽  
Jian Qiu Guo ◽  
Michael Dudley
Keyword(s):  
High Temperature ◽  
Basal Plane ◽  
Dislocation Motion ◽  
Temperature Treatment ◽  
Dislocation Dynamics ◽  
High Temperature Treatment ◽  
Velocity Measurements ◽  
Basal Plane Dislocation ◽  
Induced Motion

Direct observation of thermal gradient induced motion of basal plane dislocations by in-situ synchrotron X-ray topography imaging of PVT-grown 4H-SiC wafers subject to high temperature treatment has provided an opportunity to analyze the movement of dislocations. Dislocations with Burgers vector along the off-cut [11-20] direction were found to be the only dislocations involved in deformation during heat treatment and the segments of dislocations used for velocity measurements were found to be either pure screw comprised of both Si-and C-core partials or 60° dislocations comprised of purely Si cores. Using the kink-diffusion model, the activation energies for dislocation motion have been calculated from the velocity data for each of these dislocation types and found to be 3.28eV for pure screw and 2.21eV for 60° dislocation segments, respectively.

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