Effect of Forming Pressure on Electrical Conductivity of Sintered SiC

For application to electronic devices, the relationship between manufacturing conditions and electrical properties of SiC was investigated. High-β phase silicon carbide powder was formed into cylindrical pellet at various pressures between 50MPa and 350MPa, and was sintered at 2100°C for 0.5h in a vacuum furnace. Electrical conductivity and relative density were measured, and microstructures were observed using a scanning electron microscope (SEM). The electrical conductivity of specimens decreased from 8×10-5S/m to 4×10-6S/m with increasing the forming pressure from 50MPa to 250MPa. Whereas the density and the microstructure slightly depended on the forming pressure. For the specimens formed above the pressure of 250MPa, the electrical conductivity and density showed constant value regardless of the forming pressure.