Bulk and epitaxial growth of silicon carbide

The high-efficiency conversion of threading screw dislocations (TSDs) in 4H-SiC by solution growth provides an efficient method of obtaining ultra high-quality SiC crystals. The behavior of TSDs on on-axis and off-axis 4H-SiC0001 seed crystals was investigated by synchrotron X-ray topography. Almost all TSDs in the off-axis Si-face seed crystal were converted to Frank-type stacking faults on the basal planes. The conversion ratio of TSDs was highly influenced by the surface polarity of the seed crystal. The stacking faults laterally propagate toward the outside of the crystal.

https://iopscience.iop.org/article/10.1143/APEX.5.115501/pdf

High-Efficiency Conversion of Threading Screw Dislocations in 4H-SiC by Solution Growth

Top-seeded solution growth of three-inch-diameter 4H-SiC using convection control technique

Growth rate and surface morphology of 4H–SiC crystals grown from Si–Cr–C and Si–Cr–Al–C solutions under various temperature gradient conditions

Evolution of threading screw dislocation (TSD) conversion during the solution growth of 4H-SiC on a vicinal crystal of 4H-SiC(0001) was investigated by synchrotron X-ray topography. Selecting appropriate X-ray wavelength and g vector, we can change the penetration of X-ray, and the dislocation behaviors with the different depth were successfully observed. Evidently TSDs parallel to the c-axis having c-component Burgers vector were changed into defects on the (0001) basal planes with the same Burgers vector as the TSDs, propagating to the [112¯0] step-flow direction by advancing macrosteps during the solution growth. The TSD conversions stochastically took place during the growth. The conversion rate was almost uniform and finally almost all TSDs were converted to the basal plane defects. The conversion rate was low at the very early stage of the growth, which implies that the macrosteps were not formed at the initial stage of the solution growth.

Evolution of threading screw dislocation conversion during solution growth of 4H-SiC

We report a marked reduction in the dislocation density of a 4H-SiC crystal using a high-efficiency dislocation conversion phenomenon. During the solution growth, threading dislocations were efficiently converted to basal plane defects by the step flow of macrosteps. Utilizing this dislocation conversion phenomenon, we achieved the marked reduction of threading dislocation density. Consequently, the threading screw dislocation density was only 30 cm−2, which was two orders of magnitude lower than that of the seed crystal. The 4H-SiC polytype of the seed crystal was replicated in the grown crystal, which was attributed to the spiral growth owing to a few remaining threading screw dislocations upstream of the step flow.

https://iopscience.iop.org/article/10.7567/APEX.7.065501/pdf

Low-dislocation-density 4H-SiC crystal growth utilizing dislocation conversion during solution method

Different behavior of threading edge dislocation conversion during the solution growth of 4H–SiC depending on the Burgers vector

Polytype transformations on the 4H-SiC(0001) Si face during top-seeded solution growth have been investigated by transmission electron microscopy and micro-Raman spectroscopy. 4H-, 15R-, and 6H-SiC...

Yuji Yamamoto

Papers

High-Efficiency Conversion of Threading Screw Dislocations in 4H-SiC by Solution Growth

Evolution of threading screw dislocation conversion during solution growth of 4H-SiC

Low-dislocation-density 4H-SiC crystal growth utilizing dislocation conversion during solution method

Different behavior of threading edge dislocation conversion during the solution growth of 4H–SiC depending on the Burgers vector

Polytype Transformation by Replication of Stacking Faults Formed by Two-Dimensional Nucleation on Spiral Steps during SiC Solution Growth