Investigation of the Growth Kinetics of SiC Crystals during Physical Vapor Transport Growth by the Application of In Situ 3D Computed Tomography Visualization

Abstract

Computed tomography using X‐rays is applied during the bulk growth of silicon carbide (SiC) to investigate growth kinetics in situ during the physical vapor transport process. In addition to the standard SiC source material, in particular, a pure solid source SiC block is used. It is found that the growth rate is lowered as the sublimation of gaseous species is limited to the top part of the solid source. The morphological changes in the source area during growth differ significantly compared with the process when conventional powder is used. The formation of multiple growth centers on the surface of the seed is monitored in situ with a computed tomography system. In a series of experiments, the influence of the supersaturation on the growth is examined. The in situ computed tomography shows that the curvature of the growth interface is stronger influenced by the thermal field at higher pressures. A high supersaturation leads to the formation of rather smooth surface morphologies, whereas the formation of large steps on the surface is induced at lower supersaturations.

Impact of Mechanical Stress and Nitrogen Doping on the Defect Distribution in the Initial Stage of the 4H-SiC PVT Growth Process

“…Computed tomography using X-rays can be applied to monitor the growing crystal and the morphology change of the powder source during and after the growth process. While this allows optimizations regarding the growth kinetics of PVT, other process parameters cannot be evaluated [ 22 , 23 ].…”

Investigation of the Nucleation Process during the Initial Stage of PVT Growth of 4H-SiC

“…The growth cell is equipped with computer tomography (CT). The detailed setup is described in [2,3]. During the growth, CTs are made at different stages of growth.…”

“…In this way, it is possible to observe the crystal during growth and to draw conclusions about the existing growth rate or growth conditions. The detailed setup is described in [2,3]. During the growth process several CTs are made.…”

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 ].…”