Preferential orientation in metal nitride deposited by the UBM system

This work was aimed at studying the influence of ion bombardment on the preferred orientation (OP) of transition metal nitrides (TMN) produced by the reactive sputtering technique with a variable unbalanced magnetron through permanent magnets. Tita- nium nitride (TiN) coatings were thus studied by varying two parameters: ion-atom ratio on the substrate (Ji/Ja) and nitrogen flux. Deposition conditions were as follows: 7 mTorr working pressure, ~ 380oC substrate temperature, 2 and 8.5 sccm nitrogen flux and 245-265 discharge power. The results showed that preferred orientation (111) and the crystalline behaviour of the produced coatings depended more on nitrogen flux than on ion bombardment. Similarly, micro-hardness measured on films deposited on steel AISI-M2 substrates increased from 1600 to 2000 HV0.025 when nitrogen flux was increased