For power semiconductor applications, SiC single crystals are manufactured by sublimating high-purity SiC sources at high temperatures ranging from 2100 to 2500°C, using the physical vapor transport (PVT) method. Currently, commercial substrates are typically produced at a growth rate of 0.2 to 0.4 mm/h via the PVT method, which is significantly slower compared to other single-crystal materials used in semiconductor applications. The slow growth rate of SiC via the PVT method is one of the major barriers hindering the productivity of SiC substrates. Although not via the PVT method, rapid growth of SiC has been developed recently so far [1-4]. They successfully controlled the growth rate of SiC single crystals to ~9 mm/h using the high-temperature chemical vapor deposition (HTCVD) method, even achieving high-quality crystals at the growth rate of ~3 mm/h. The HTCVD method allows the use of vapor phases as the source, which originally excluded the formation of carbon dust from the solid sources and freely controlled the composition of the vapors, thereby removing the source issue hindering the rapid growth. So, the high-quality crystals were achieved under rapid growth conditions by preventing the formation of excess crystal surfaces for heat dissipation by controlling the temperature gradient at the growth interface. However, practically, SiC single crystals are currently mass-produced via the PVT method with solid SiC as the source by all suppliers. Even if it is possible to manufacture high-quality, rapidly grown SiC single crystals, adopting an entirely different process like HTCVD as a mass production process would involve considerable difficulties. For the manufacturers producing bulk SiC crystal products, there is a need for technologies that can improve the mass production of products within the existing process framework. In recent studies, therefore, we have reported a method for rapidly growing SiC single crystals using the existing PVT method [5]. Instead of the traditional powdered SiC sources, CVD-SiC crushed blocks were used in our research [5]. These blocks are not in powdered form and have a very small specific surface area, thus they can prevent the inclusion of carbon dust into the growing crystals under strong fluid flow during rapid growth, thereby preventing quality degradation of the single crystals due to source problems. Previous studies have reported growth rates up to 1.7 mm/h for SiC single crystals with a diameter of 50 mm, but the crystal quality, especially at the edges, was not satisfactory. In this study, as part of efforts to improve single crystal growth characteristics, various growth results were obtained in the growth speed range of ~0.8 to ~2.6 mm/h by controlling the vertical and horizontal temperature gradients at the growth interface, and these were compared with the temperature gradient patterns obtained from PVT simulations, aiming to gauge future directions for the rapid PVT growth method.