In this study, an aluminum-nickel-lanthanum (Al-Ni-La) alloy is introduced, for the first time, to hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) for gate metallization technology. Ni atoms in Al-Ni-La can effectively improve contact characteristic with ITO film, while La can increase the uniformity of contact resistance during film deposition compared to the conventional Al-Nd alloy. Besides, Al-Ni-La alloy has advantages of a simple process and better prevention against hillock issues, which benefits active matrix liquid-crystal display (AMLCD) manufacture. The Al-Ni-La gate thin film transistor (TFT) also exhibited reliable electrical characteristics. The process compatibility with typical TFT manufacture makes Al-Ni-La gate metallization greatly promising for AMLCD technology application.