High-density DLC films prepared using a magnetron sputter type negative ion source

Abstract

Diamond-like carbon (DLC) films have been deposited at room temperature using a magnetron sputter type negative ion source (MSNIS). The film characteristics such as density, surface roughness, film structure and thicknesses are obtained and analyzed using X-ray reflectivity (XRR), XPS and AFM methods. XRR results showed that the density of the film varies from 1.9 to 3.0 g/cm 3 with respect to the different deposition parameters. At average negative carbon ion energy 700 eV and Cs injector temperature 150 °C, the densest film (3.0 g/cm 3) was observed at 1 nm/s deposition rate. The surface roughness of the film was less than 1.0 nm in most cases for the 10-nm thickness film. XPS peak showed no Cs content on the film. The films prepared at different negative ion production yields and negative ion energies were compared. The result suggests that the density is the strong function of negative ion energy and the negative ion production yield. Higher cathode voltage induced denser film, while Cs flow rate had optimum temperature condition around 150 °C.