Effect of annealing on the temperature coefficient of resistance of tialn film deposited by facing target sputtering

As a replacement for the commercial inkjet print-head heating resistor TaN_0.8 film, the titanium aluminum nitride (TiAlN) ternary film deposited by facing target sputtering was investigated. TiAlN films were deposited on Si (100) substrates with different N₂ flow rates and annealed. It was found that the microstructure changed from columnar to smaller equi-axed grains, with improved crystallinity and a flat surface from increased N₂.The temperature coefficient of resistance (TCR) and the oxidation resistance were improved. This was due to the enhanced formation of nitride and improved crystallinity from the stable equi-axed grains when a large amount of N₂ was introduced. After rapid thermal annealing, the high N₂ film, which increased crystallinity with maintaining equi-axed grains, improved the TCR about 29%, while the low N₂ film, made of TiO₂ and an Al₂O₃ second oxide, decreased the TCR by 17%. This means that a stable equi-axed nitride phase formation using high partial N₂ is desirable with facing target sputtering for the stable TCR and anti-oxidation.