Preparation and growth mechanism of ultra-thin free-standing polycrystalline diamond film based on glass carbon substrate

Abstract

In these experiments, Ti, Si and glass carbon substrates were selected to prepare ultra-thin polycrystalline diamond films by microwave plasma chemical vapor deposition (MPCVD) using CH4/H2 as the reaction source. The overall morphology, surface morphology, composition and stress state of the prepared diamond films were characterized and analyzed by SEM, Raman and a profilometer. The results show that only diamond films grown on glass carbon substrate can be automatically peeled off to form a complete free-standing film. The crystal surface of the film grains is clear, and the film thickness is only 10 μm. Raman spectra reveal that thin films have strong sharp diamond characteristic peaks, and that the calculated residual stress is the lowest, which is −0.2161 GPa. It is expected to provide an effective new technique for the one-step growth and stripping of ultra-thin self-supported CVD diamond films.

Keywords

• ultra-thin diamond film
• free-standing
• glass carbon substrate
• film-substrate separation
• growth mechanism
• mpcvd