Control over the lateral distribution of hydrogen content in the pulsed-laser deposited diamond-like carbon films

We propose a method of controllable variation of the hydrogen content along the lateral direction of the pulsed-laser deposited DLC films. Hydrogen incorporates into the film by the adsorption of atmosphere hydrocarbon molecules on the growing surface in a vacuum chamber. The variation of hydrogen content is provided by use of the angular distribution of a carbon mass flow in a laser plume and by means of cleaning off the adsorbed hydrocarbons with help of impinging by laser-ablated carbon particles under oblique angles to the substrate. Deposition of DLC films at different angles of incidence of laser-ablated carbon flow reveals the decrease of the hydrogen content at the periphery of the film from 22 down to <3 at% as the angle changes from normal to the oblique one, while hydrogen content in the centre of the film remains nearly constant at a level of 10 at%.