Studies of the Distribution of Elementary Threading Screw Dislocations in 4H Silicon Carbide Wafer
The density and sense distribution of elementary threading screw dislocations in a physical vapor transport grown 3-inch 4H silicon carbide wafer have been studied. The density of TSDs ranges between 1.6×103/cm2 and 7.1×103/cm2 and the lowest density is observed at positions approximately half radius off the wafer center. The dislocation sense of elementary threading screw dislocations can be readily revealed by the asymmetric contrast of their images in grazing-incidence x-ray topographs using pyramidal plane reflections. The circumferential and radial distributions of the sense of elementary threading screw dislocations have been studied and no clear trends are observed in either distribution.
Akira Suzuki, Hajime Okumura, Tsunenobu Kimoto, Takashi Fuyuki, Kenji Fukuda and Shin-ichi Nishizawa
Y. Chen et al., "Studies of the Distribution of Elementary Threading Screw Dislocations in 4H Silicon Carbide Wafer ", Materials Science Forum, Vols. 600-603, pp. 301-304, 2009