An oxidation enhanced mechanical polishing technique for CVD diamond films

Abstract An oxidation enhanced mechanical polishing technique of CVD diamond films has been developed in order to expand its industrial applications. Although numerous machining methods [David G. Jeng, H.S. Tuan, Appl. Phys. Lett. vol.56 (No.20) (May 1990) p. 1968] were explored for years, including mechanical polishing, thermal chemical polishing, plasma etching, excimer laser etching, and ion beam polishing, some issues need to be studied in order to apply for large area and take cost down. In the present work, microwave plasma enhanced chemical vapor deposition (CVD) is used to obtain diamond films with full width half magnitude (FWHM) less than 10 wave numbers at 1332 cm −1 Raman peak. Slurry containing 0.4 M potassium permanganate (KMnO 4 ) and diamond powders was supplied to a grooved ceramic plate at 70 °C. During the polishing process, diamond film was hold against rotational ceramic plate with transverse oscillation. A profilometer, an atomic force microscope, and a scanning electron microscope have been used to evaluate the surface states of diamond films before and after polishing. The average surface roughness of diamond film performed by the current technique is less than 20 nm. This result reveals a great potential for commercializing.