Improved electrical and material characteristics of HfTaO gate dielectrics with high crystallization temperature

N -type metal-oxide-semiconductor field-effect transistors (N-MOSFETs) using HfTaO with varying Ta composition (20%, 30%, 40%, and 50%) have been fabricated and characterized. Crystallization temperatures of HfTaO with varying Ta composition were also measured. It was found that HfTaO with 40% Ta exhibited the highest crystallization temperature of 900 °C, while 35% and 52% HfTaO showed crystallization temperature of 800 °C. The results demonstrate that HfTaO N-MOSFETs exhibit higher electron mobility than controlled HfO2 devices. Among them, the transistor with 40% Ta shows the highest electron mobility.