Bismuth precursors for atomic layer deposition of bismuth-containing oxide films

Abstract

Several bismuth amides and a bismuth thioamidate compound were synthesized and characterized in order to find volatile bismuth precursors for atomic layer deposition (ALD) of oxide materials. Crystal structures of Bi(N(SiMe3)2)3 and Bi(SC(Me)NPri)3 are reported. Based on precursor characterization Bi(N(SiMe3)2)3 was selected for film deposition experiments. It was found that alternate surface reactions of Bi(N(SiMe3)2)3 and H2O can be used for ALD of amorphous BiOx, Bi–Ta–O and Sr–Bi–Ta–O at 190–200 °C. After post-deposition annealing at 800 °C in oxygen the SrBi2Ta2O9 layered perovskite phase was obtained.