SiC nanoparticles are synthesized by r.f. thermal plasma chemical vapour deposition using a chemical system of SiH4-C2H4-H2-Ar. The average particle size is about 30 nm, and its shape is nearly spherical. The product is β-SiC and high pure with total metal impurity of less than 1 ppm. High pure and fully densified SiC body can be made by hot-pressing the sub-micron sized SiC powder added SiC nanoparticles without any sintering additives. They show electrical conductivity, high thermal conductivity and better properties of thermal shock resistance and chemical resistance compared with conventional SiC ceramics. Furthermore, Al2O3-SiC nano-composite can be made by using SiC nanoparticles easily. These functional ceramics from nanoparticles are the most promising materials for the semiconductor manufacturing process. Up to now, various sintered parts, such as heater, susceptor, pulse heat tool, shower plate and electrical static chuck, etc. have been developed and widely used in the semiconductor industry.