Polishing of diamond thick films by Ce at lower temperatures

An efficient coarsely polishing and thinning method for CVD diamond films is achieved using solid or molten rare earth—Ce at the lower temperatures such as 700 °C for 2 h and 820 °C for 0.5 h. The factors affecting the surface roughness (Ra) and the rate of removal of diamond films are discussed thoroughly in this paper. In addition, the polishing mechanism is investigated primarily. The results show the content of diamond on the surface of the polished films has increased to a certain extent due to the etching out of impurities mostly at the grain boundaries and the FMHW of diamond Raman peak for polished diamond films has a visible increase. A large number of diamond films may be polished simultaneously at the temperatures lower than reported previously without noticeable contaminants on the polished surfaces of diamond films.