A new reactive pulsed laser ablation technique for the deposition of hard carbon and carbon-nitride thin films

摘要

A new configuration of the pulsed laser deposition (PLD) technique for improving the growth of thin films in a gas ambient is described. A nozzle arrangement is used to create high pressure N_2 and He pulses in the region above an ablated carbon target for the formation of C:N and C thin films. Films deposited by both the standard and the new configuration are compared in terms of their mechanical properties, nitrogen concentration and microstructure. When the standard configuration is used, the maximum values attained for the nitrogen concentration and film microhardness are 32.25/100 and 13 GPa, respectively. When the pulsed N_2 nozzle configuration is used, the nitrogen concentration (30.58/100) is almost equal to the highest value attained with the standard configuration but the film microhardness is higher (15.8 GPa). When the He nozzle is used the film microhardness increases further, up to a value of 34 GPa. Interestingly, the elastic recovery of most films reaches relatively high values, between 60/100 and 70/100. In all cases the films are amorphous and macroparticle inclusions are observed.