Influence of the growth interface shape on the defect characteristics in the facet region of 4H-SiC single crystals

Abstract

Two 75mm 4H-SiC single crystals are grown by the physical vapor transport (PVT) technique, using different insulation materials. The insulation material of higher thermal conductivity led to an increased radial temperature gradient. The evolution of the growth front was monitored using the in-situ computed tomography (CT). A slightly bent growth interface and a bigger facet are formed during the growth applying a lower radial temperature gradient while a smaller facet and steeper crystal flanks are formed in the case of the larger radial temperature gradient. Micropipes are deflected laterally by large surface steps on the steep crystal flanks and a reduction of threading edge dislocations by 60% is revealed by KOH defect etching.

Numerical Analysis of Dislocation Density of SiC Crystals Tilted from [0001] Toward [12¯10]$[ {1\bar 210} ]$ and [11¯00]$[ {1\bar 100} ]$ Grown by Physical Vapor Transport

“…[8] Several scholars have reported that crystal growth along a tilt from [0001] toward [1 210] is suitable for stabilizing polytype. [9,10] However, to the best of our knowledge, there is no study on the dislocation analysis of crystals along a tilt from [0001] toward [1 210] and [1 100] in conjunction with stress analysis. In this paper, we studied dislocation density using the Alexander-Haasen model with 3D and time-dependent calculations reported elsewhere, [11,12] including crystal growth and cooling processes.…”

“…[ 8 ] Several scholars have reported that crystal growth along a tilt from [0001] toward $$[ {1\bar 210} ]$$ is suitable for stabilizing polytype. [ 9,10 ] However, to the best of our knowledge, there is no study on the dislocation analysis of crystals along a tilt from [0001] toward $$[ {1\bar 210} ]$$ and $$[ {1\bar 100} ]$$ in conjunction with stress analysis.…”

Novel Photonic Applications of Silicon Carbide

“…For more specific inquiries of the growth process, advanced 3D imaging can be employed. Such sophisticated systems are not commercially viable due to the technical complexities; however, in an R&D environment, they have been proven to be incredibly valuable in considering problems such as the evolution of the crystal’s facet during growth [ 184 ], the specific morphology of the powder source for the determination of dynamic source material properties [ 185 ], as well as the impact of the curvature of the growth interface on the defect distribution in the resulting crystal [ 186 ].…”

Undulated Step Structure on the (0001¯) Facet of Physical Vapor Transport-Grown 4H-SiC Crystals

“…The step structure on the as-grown surface of SiC crystals has been studied by several research groups [6][7][8][9][10][11][12]. On the (0001) facet of 4H-SiC crystals grown in the c-axis direction, surface steps of half-unit cell height (0.5 nm) were predominantly observed, and they were often bunched into macrosteps of heights of approximately 6-10 nm.…”