Excimer laser-assisted planarization of thick diamond films

The planarization of polycrystalline diamond films is critical for a large number of industrial applications. We have investigated a laser-assisted method for planarization of thick diamond films. This method is based on the application of excimer laser combined with simultaneous rotation of the sample. Thick diamond films (average surface roughness: ∼20 μm and thickness ∼500 μm) were fabricated by plasma jet chemical vapor deposition process. The planarization of diamond films was found to be critically dependent on the angle of incidence of laser beam. Smoother surfaces were obtained at higher incidence angles (θ = 80°). However, by combination of sample rotation with laser irradiation at higher incidence angles (θ = 80°), maximum surface planarization was achieved. Under optimum conditions, the surface roughness of the samples were reduced from 20 to 0.1 μm. The mechanisms for surface planarization of thick diamond films are discussed.