OXIDATION BEHAVIOR OF ALN TIN DOUBLE-LAYE R FILMS PREPARED BY RF REACTIVE SPUTTERING/

TiN films have many useful properties such as extreme high microhardne ss, resistance to wear, resistance to friction, and so on. However, re latively poor resistivity against oxidation is shown at high temperatu re. The purpose of this work is to investigate the oxidation behavior of the AlN/TiN double layer films as an alternative to TiN films. TiN single layer films (thickness; 300 nm) and AlN (100 nm)/TiN(200 nm) do uble layer films were deposited onto (001) Si wafers using rf reactive sputtering apparatus with two planar magnetron type cathodes. The tar gets were pure Ti ( >99.9%) and pure Al (> 99.999%) disks (70 mm in di ameter). An Ar+N-2 mixed gas (Ar : N-2=1 : 1, total pressure 0.4 Pa) w as used as the sputtering gas. The substrate temperature and rf power were kept constant at R.T. and 300 W, respectively. The deposited film s were annealed in the air environment at 400 similar to 700 degrees C for 60 min and then subjected to Auger depth profiling. The as-deposi ted AlN/TiN interface appeared to be free from contamination and inter diffusion. There was no evidence of the existence of compound formatio n at the interface. X-ray diffraction analysis revealed that the AIN c rystalline layer had an 00. 2 preferred orientation on the weakly 001 oriented TiN layer. The oxide layer of similar to 200 nm was formed on the TiN single layer films by annealing at 600 degrees C for 60 min. On the contrary, the AlN/TiN double layer films showed excellent oxida tion resistance even when annealing at 700 degrees C.