Temperature dependence of double Shockley stacking fault behavior in nitrogen-doped 4H-SiC studied by in-situ synchrotron X-ray topography

• Published in: Acta materialia 2020-08, Vol.194, p.387-393
• Main Authors: Fujie, Fumihiro, Harada, Shunta, Hanada, Kenji, Suo, Hiromasa, Koizumi, Haruhiko, Kato, Tomohisa, Tagawa, Miho, Ujihara, Toru
• Format: Article
• Language: English
• Subjects: Dislocation gliding; In situ; Silicon carbide; Stacking faults; Synchrotron X-ray topography
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2020.04.019

We observed the behavior of double Shockley stacking faults (DSFs) in 4H-SiC crystals with nitrogen concentrations of 1.0 × 1019–2.6 × 1019 cm−3 over an extensive temperature range (1380–1910 K) by in-situ synchrotron X-ray topography. For a nitrogen concentration of 2.6 × 1019 cm−3, the expansion velocity of the DSFs exponentially increased with temperature in the range from 1370 to 1650 K. In contrast, at a nitrogen concentration of 1.0 × 1019 cm−3, this velocity decreased above 1610 K and the DSFs shrank above 1730 K. The DSF energy, the magnitude of which is the driving force on partial dislocation (PD) movement, was quantitatively estimated from the radius of the curvature of bowed-out partial PDs pinned by threading screw dislocations (TSDs), showing a positive temperature dependence and lying in the range from −0.6 to 0.8 mJ/m2 for 1630–1910 K at a nitrogen concentration of 1.0 × 1019 cm−3. The DSF expansion and shrinkage behavior can be understood by the simple temperature and nitrogen concentration dependence of the DSF energy. [Display omitted]