Purity Evaluation of Highly Oriented Cubic Silicon Carbide Using Micro-Raman Spectroscopy

Characteristics of the Discoloration Switching Phenomenon of 4H-SiC Single Crystals Grown by PVT Method Using ToF-SIMS and Micro-Raman Analysis

“…Figure 5 a,b shows the XRD patterns and X-ray rocking curves of the Case I and Case II 4H-SiC single crystals in the (0004) direction, wherein it can be seen in Figure 4 a that all samples prepared by PVD were preferentially grown along strong (004) planes. In this figure, the XRD peaks observed at 35.6°, 38.1°, 43.2°, 49.7°, 57.2°, 65.7°, and 74.9° were attributed to the (004), (012), (013), (014), (015), (016), and (017) planes of the 4H-SiC phase, respectively [ 15 , 16 , 19 ]. All peaks were in good agreement with ICSD card 98-016-4971.…”

“…As outlined in Figure 8 and Table 5 , the concentration of each impurity was converted into atoms cm −3 , and the donor–acceptor recombination ratios (RDAs) of C D−A and 2C B /(C N − C B ) were calculated using Equation (1) [ 15 , 21 , 22 ], wherein the B, Al, and N concentrations are defined as C B , C Al , and C N , respectively. The parameter C D−A was calculated as a function of C B − (C Al − C N ) [ 16 ] to give the values listed in Table 5 . C D−A = ln C B − (ln C Al − ln C N ), …”

“…The residual acid salt was removed by volatilization, and any excess oxygen present in the SiC was removed through denitrification under heating at 105 °C under reduced pressure in an argon environment. All other impurities present in the synthesized SiC were eliminated through the decarburization method by heat treatment at 850 °C for 1 h under oxygen atmosphere conditions to give a dried 3C-SiC powder with a purity of >90% [ 15 , 16 ]. The method for removing excess oxygen present in 3C-SiC powder was explained in detail as follows.…”

“…Then, the residual oxygen was purified by the OH substitution of acid through esterification at 105 °C on a hot plate [ 15 , 16 ]. Subsequently, the obtained powder was sieved through a 100 µm mesh to remove the fine and coarse particles.…”

“…The XRD patterns of the 3C-SiC powder showed peaks corresponding to 3C-SiC (β-SiC phase), as shown in Figure 1 . The peaks at 35.7°, 41.2°, 59.9°, and 71.6° are attributed to the (111), (200), (220), and (311) planes of the β-SiC phase, respectively [ 15 , 16 , 17 , 18 ].…”