Epitaxial growth and thermal stability of Fe_4N film on TiN buffered Si(001) substrate

摘要

Epitaxial Fe_4N thin films were grown on TiN buffered Si(001) substrate by dc reactive sputtering deposition at different substrate temperatures. Fe_4N films epitaxially grew on TiN within the substrate temperature range from 250 to 350 °C. Lower than 250 °C there will be some other Fe_xN compounds formed and higher than 400 °C there will be only Fe left. Fe_4N is metastable and the postannealing process in vacuum will decompose Fe_4N film to Fe. However, introducing 30% N_2 in the postannealing atmosphere can stabilize the Fe_4N up to 350 °C in the (Ar,N_2) gas mixture. The surface roughness of the epitaxial Fe_4N films decreases with film thickness. There is in-plane biaxial magnetic anisotropy of epitaxial Fe_4N(001) on Si(001) with the [100] easy direction.