Sputter deposition from a Ti2AlC target: Process characterization and conditions for growth of Ti2AlC

Sputter deposition from a Ti2AlC target was found to yield Ti–Al–C films with a composition that deviates from the target composition of 2:1:1. For increasing substrate temperature from ambient to 1000 °C, the Al content decreased from 22 at.% to 5 at.%, due to re-evaporation. The C content in as-deposited films was equal to or higher than the Ti content. Mass spectrometry of the plasma revealed that the Ti and Al species were essentially thermalized, while a large fraction of C with energies > 4 eV was detected. Co-sputtering with Ti yielded a film stoichiometry of 2:0.8:0.9 for Ti:Al:C, which enabled growth of Ti2AlC. These results indicate that an additional Ti flux balances the excess C and therefore provides for more stoichiometric Ti2AlC synthesis conditions.