Showa Denko K.K. has concluded a long-term supply contract with ROHM Co. Ltd. (ROHM), to supply SiC epitaxial wafers for power semiconductors (SiC epi-wafers) for plural years. ROHM decided to conclude this ling-term contract because the company appreciated high-quality and stable supply system of SDK’s SiC epi-wafers. ROHM continues developing semiconductors, and therefore, this long-term contract will further strengthen technical cooperation between SDK and ROHM on improvement in qualities of SiC epi-wafers including homogeneity in properties and low density of surface defects.