Using cosputtering system, TaAl thin films for the heating resistor of the inkjet printer head are deposited and characterized by XRD and AES. An analysis of the TaAl films by XRD (X-Ray Diffraction) shows that the TaAl films have β-Ta series structure. Interdiffusion of Ta/Al or TaAl/Al does not make serious problems when the temperature and time of operation is 450℃ up tp 5 hours, respectively. Effects of oxygen on TaAl films are critical. The resistivity of TaAl films and the absolute temperature coefficient of resistance increases with the oxygen concentration. Therefore, the cooperation of oxygen to the TaAl films should be avoided. To decrease the contact resistance between Al and TaAl, TaAl and Al must be deposited in the same chamber, because the increase in the contact resistance due to the rapid oxidation rate of TaAl. Presputteing before deposition of the films is the most critical step to get good films with low contact resistance and smooth surface. High temperature aging experiments show that TaAl films should undergo pre-heat treatment above the operation temperature before using as resistors. $10^8$ current pulse stress does not degrade TaAl films noticeably even with 2.5 times higher power stress than the normal operation condition.
