Development of Solvent Inclusion Free 4H-SiC Off-Axis Wafer Grown by the Top-Seeded Solution Growth Technique

This study reports our newly developed technology for SiC solution growth. In particular, we succeed in completely suppressing solvent inclusions, which have been a serious technological problem peculiar to the solution growth method. Then, we fabricate two-inch-diameter 4° off-axis SiC wafers without solvent inclusions. Moreover, we performed their crystal defects evaluation. It was found that our wafers were low resistance n-type 4H-SiC and contain almost no basal plane dislocation. As a result, the superior quality of our solution-grown crystal was confirmed.

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Solution Growth and Crystallinity Characterization of Bulk 6H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.645-648.33 ◽

2010 ◽

Vol 645-648 ◽

pp. 33-36 ◽

Cited By ~ 13

Author(s):

Nobuyoshi Yashiro ◽

Kazuhiko Kusunoki ◽

Kazuhito Kamei ◽

Akihiro Yauchi

Keyword(s):

Grown Crystal ◽

Solution Growth ◽

Growth Technique ◽

Rocking Curve ◽

Long Time ◽

Crystal Seed ◽

Koh Etching ◽

Light Green ◽

Solution Growth Technique

The stable long time growth with the use of Si -C-Ti ternary solution was realized　by improving the thermal condition during the growth. We have succeeded in obtaining a maximum 10 mm thick bulk 6H-SiC crystal, which is the largest bulk crystal ever obtained by the solution growth technique. The obtained crystal was free of cracks and exhibited a homogeneous light green color. The crystallinity of the grown crystal was characterized by X-ray rocking curve measurements using (0006) reflection and by the molten KOH etching. The mapping of the full width at half maximum (FWHM) revealed the average FWHM around 30 arc seconds and the minimal FWHM under 16 arc seconds. The etch pit density (EPD) was typically in the range between 104 and 105 cm-2, which was comparable to that of the crystal seed.

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Effect of Melt-Back Process on the Quality of Grown Crystal in SiC Solution Growth

Materials Science Forum ◽

10.4028/www.scientific.net/msf.963.75 ◽

2019 ◽

Vol 963 ◽

pp. 75-79 ◽

Cited By ~ 3

Author(s):

Kotaro Kawaguchi ◽

Kazuaki Seki ◽

Kazuhiko Kusunoki

Keyword(s):

Dislocation Density ◽

Grown Crystal ◽

Early Stage ◽

Seed Crystal ◽

Solution Growth ◽

Crystal Quality ◽

Top Seeded Solution Growth ◽

Koh Etching

We investigated the effect of a melt-back process on the quality of the grown crystal in 4H-SiC solution growth. In our experiments, the crystal was grown by top-seeded solution growth (TSSG) method with and without melt-back, following which the quality of the obtained crystals was compared. When solution growth was carried out without melt-back, solvent inclusions and a different polytype were observed. When molten KOH etching was conducted, the dislocation density in the crystals at the early stage of growth became much higher than that in a seed crystal. Solvent inclusions, a different polytype, and an increase in dislocations were suppressed when solution growth was performed with melt-back. It was confirmed that melt-back is necessary to prevent the deterioration of crystal quality at the early stage of solution growth.

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