Titanium nitride film was grown on MgO(001) substrate by plasma-assisted molecular beam epitaxy and then oxidized by oxygen plasma. Reflection high-energy electron diffraction was employed to in situ monitor the process of growth and oxidation. After the TiN film was oxidized for a moment, spots among main streaks were observed in reflection high-energy electron diffraction pattern, which should be attributed to the isolated surface reconstruction domains disorderedly distributing on flat surface. Subsequently, the spots gradually evolved to streaks so that more clear reflection high-energy electron diffraction patterns of (2 x 1) surface reconstruction were observed. It was argued that the disordered and isolated reconstruction domains congregated to large domains or even perfect reconstruction surface with oxidation time evolving. After oxidation, a series of characterization methods were applied to study the TiO2 phase, which consistently confirmed that the phase of oxidized titanium nitride was anatase and not rutile.

Surface Reconstruction Evolution and Anatase Formation in the Process of Oxidation of Titanium Nitride Film. S.X.Wu, Y.J.Liu, X.J.Xing, X.L.Yu, L.M.Xu, Y.P.Yu, S.W.Li: Journal of Applied Physics, 2008, 103[6], 063517