Effect of temperature on conversion of basal plane dislocations to treading edge dislocations during 4H-SiC homoepitaxiy

•The effect of temperature on conversion of BPDs to TEDs is studied.•The origin of TEDs in epilayer is distinguished by using the molten KOH etching.•During epitaxial growth, the conversion process of BPDs is discussed.•Low BPD density of epilayer is obtained by the optimization of temperature. 4H-SiC homoepitaxial layer grown on 4° off-axis substrates is performed at various growth temperature by using the traditional chemical vapor deposition. The effect of growth temperature on propagation of basal plane dislocations from substrate to epitaxy was studied using the deep KOH etching and Synchrotron reflection X-ray topography, and the conversion mechanism was also investigated. It is found that the majority basal plane dislocations are converted to threading edge dislocations during epitaxial growth. Meanwhile, the two types of threading edge dislocations in epitaxial layer are observed after KOH etch. By the optimization of growth temperature, high quality epitaxial wafer with extremely low basal plane dislocations density (