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

A new configuration of the pulsed laser deposition (PLD) technique for impr oving the growth of thin films in a gas ambient is described. A nozzle arra ngement is used to create high pressure N-2 and He pulses in the region abo ve an ablated carbon target for the formation of C:N and C thin films. Film s deposited by both the standard and the new configuration are compared in terms of their mechanical properties, nitrogen concentration and microstruc ture. When the standard configuration is used, the maximum values attained for the nitrogen concentration and film microhardness are 32.25% and 13 GPa , respectively. When the pulsed N, nozzle configuration is used, the nitrog en concentration (30.58%) is almost equal to the highest value attained wit h 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 rea ches relatively high values, between 60% and 70%. In all cases the films ar e amorphous and macroparticle inclusions are observed. (C) 1999 Elsevier Sc ience B.V. All rights reserved.