Paper Titles
Preface
The Elusive Bulk Inclusion, Sizing, Wafer- and Ingot-Level Localization and Their Effect on Dislocation Generation and Epitaxial Defectivity in 4H-SiC
p.1
Formation Mechanism and Reduction of Surface Pits on 4H-SiC Epitaxial Layer
p.9
Minority Charge Carrier Lifetime for Evaluating 4H-SiC Epitaxial Growth by Microwave Detected Photoconductivity Decay
p.15
DLTS Analysis of Deep Levels in 4H-SiC Schottky Barrier Diode under Different Measurement Parameters
p.21
Influence of Temperature Field and Doping on BPD Distribution in 8-Inch 4H-SiC Substrates
p.27
DC and RF Local Electrical Properties of Macrostepped 4H-SiC Surface Probed by Scanning Spreading Resistance Microscopy and Scanning Microwave Impedance Microscopy Modes
p.33
Advanced Defects Study and Monitoring in New Generation 4H-SiC Devices
p.39
Investigating the Temperature Dependence of Charge Carrier Lifetime in Low-Doped Epitaxial 4H-SiC Layers
p.45

Formation Mechanism and Reduction of Surface Pits on 4H-SiC Epitaxial Layer

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Abstract:

Surface pits in silicon carbide (SiC) epitaxial layers have a significant impact on various types of SiC devices, potentially causing electric field concentration and degrading device performance. The formation mechanism of surface pits remains unclear. In this work, the mechanism was investigated through the molten KOH etching experiments, and we confirmed that surface pits originate from dislocation defects in the substrate, particularly TSDs. The dislocations negatively impacted the step-flow growth of epitaxy, leading to pit formation. Further investigations into the effects of growth temperature, C/Si ratio, and epitaxial-layer thickness on pit formation revealed that low temperatures and silicon-rich conditions could effectively suppress pit formation. Both the density and size of surface pits increased significantly with the increase in epitaxial layer thickness. Therefore, this work proposes a model for the formation mechanism of surface pits, where the competition between step-flow growth and spiral growth is a key factor in controlling the size of surface pits.

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Periodical:

Defect and Diffusion Forum (Volume 452)

Pages:

9-14

DOI:

https://doi.org/10.4028/p-S58gNE

Citation:

Cite this paper

Online since:

May 2026

Authors:

Wei Ning Qian*, Fei Hong Huang, Ji Nan Li, Gan Feng, Yong Qiang Sun, Jian Hui Zhao, Jun Yong Kang

Keywords:

150 mm 4H-SiC, Hot-Wall Reactor, Surface Pit

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Creative Commons CC BY 4.0

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* - Corresponding Author

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