Removal of Mechanical-Polishing-Induced Surface Damages on 4H-SiC Wafers by Using Chemical Etching with Molten KCl+KOH

Yong Zhao Yao; Yukari Ishikawa; Yoshihiro Sugawara; Koji Sato

doi:10.4028/www.scientific.net/MSF.778-780.746

Paper Titles

Hydrogen Effects in ECR-Etching of 3C-SiC(100) Mesa Structures
p.730

Off-Orientation Influence on C-Face (0001) 4H-SiC Surface Morphology Produced by Etching Using Chlorine Trifluoride Gas
p.734

Development of Silicon Carbide Dry Etcher Using Chlorine Trifluoride Gas
p.738

Investigation of Trenched and High Temperature Annealed 4H-SiC
p.742

Removal of Mechanical-Polishing-Induced Surface Damages on 4H-SiC Wafers by Using Chemical Etching with Molten KCl+KOH
p.746

Thinning of a Two-Inch Silicon Carbide Wafer by Plasma Chemical Vaporization Machining Using a Slit Electrode
p.750

A Novel Grinding Technique for 4H-SiC Single-Crystal Wafers Using Tribo-Catalytic Abrasives
p.754

Dicing of SiC Wafer by Atmospheric-Pressure Plasma Etching Process with Slit Mask for Plasma Confinement
p.759

Multi-Wire Electrical Discharge Slicing for Silicon Carbide Part 2: Improvement on Manufacturing Wafers by Forty-Wire EDS
p.763

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Removal of Mechanical-Polishing-Induced Surface Damages on 4H-SiC Wafers by Using Chemical Etching with Molten KCl+KOH

Abstract:

High temperature (>1000 °C) chemical etching using molten KCl or molten KCl+KOH as the etchant has been carried out to remove the mechanical-polishing (MP) induced damage layer from 4H-SiC surface. Atomic force microscopy observations have shown that line-shaped surface scratches that have appeared on the as-MPed surface could be completely removed by KCl-only etching or by KCl+KOH etching (KCl:KOH=99:1 in weight) at ~1100 °C. Between the two recipes, KCl+KOH etching has shown a higher etch rate (6~7 times) and is able to remove ~9 μm and ~36 μm-thick damage layer from the Si (0001) and the C(000-1) surface, respectively. Besides, KCl+KOH etching seems to have formed a Si (0001) surface covered with atomic steps while KCl-only etched surface is featured with nanometer-scale pores.