关键词: 8英寸SiC单晶衬底, 物理气相传输法, X射线摇摆曲线, 微管密度, 翘曲度和弯曲度, 位错密度

Abstract: A SiC single crystal boule with a diameter of 209 mm was grown by physical vapor transport (PVT) method with a diameter expansion technique. Standard 8-inch SiC single crystal substrates were fabricated by using the processes of multi-wire sawing, grinding, polishing and cleaning. Crystal polytype, crystal quality, micropipes, resistivity, stress, wafer shape, dislocation of a randomly selected 8-inch substrate were characterized by Raman spectrometer, high-resolution X-ray diffractometer, optical microscope, resistivity tester, polarization stress meter, wafer flatness tester, and dislocation detector. Raman spectra show that 8-inch substrate consists only 4H polytype. X-ray rocking curves illustrate full-width at half-maximum of the (004) peak between 10.44″ and 11.52″. Micropipe density is 0.04 cm^-2 and the average resistivity is 0.020 3 Ω·cm. There is no stress concentration zone in the substrate with an evenly distributed stress. Warp and bow are 17.318 μm and -3.773 μm, respectively. The average dislocation density is 3 293 cm^-2 by scanning the full area of the molten KOH etched 8-inch substrate, among which the density of threading screw dislocation(TSD), threading edge dislocation(TED) and basal plane dislocation(BPD) are 81 cm^-2, 3 074 cm^-2 and 138 cm^-2, respectively. All results indicate the high quality of the 8-inch n type 4H-SiC substrate, which reaches world-class levels according to the comparsion with the industry standards.

Key words: 8-inch SiC single crystal substrate, physical vapor transport mehtod, X-ray rocking curve, micropipe density, warp and bow, dislocation density