Measurements of the mechanical properties and structure of a DLC film before and after F-19 irradiation

Amorphous hydrogenated carbon (a-C:H) coated silicon wafer, also known as diamond like carbon (DLC), was irradiated using fluorine (F-19) beam at the 9 MV Tandem Van de Graaff accelerator, IFIN-HH Bucharest. Investigations of possible changes that appear following exposure to irradiation are presented in this work as a new atomic force microscopy (AFM) application. Nanoindentation coupled with AFM technique has been used to measure the hardness of the DLC film before and after the irradiation. Twenty-four indentations were made at four different points on the DLC film (thickness 510 nm) using the same diamond tip, force and under the same conditions. The results show that the values for the roughness and hardness increased for the irradiated DLC film the with respect to the unirradiated one. This film was also characterized by Fourier Transform Attenuated Total Reflectance (FT-AIR).