The molecular structure of tris[bis(trimethylsilyl)amido]lutetium, [(Me3Si)2N]3Lu, is investigated. An agostic interaction is found between Lu and the Si atom of the silyl group. The performance of [(Me3Si)2N]3Lu as precursor to deposit Lu silicate layers by atomic layer deposition using either H2O or O3 as oxygen source is studied. Si incorporation in the films is revealed: [(Me3Si)2N]3Lu thermal decomposition and the mentioned agostic interaction contribute both to the phenomenon. [(Me3Si)2N]3Lu thermal decomposition also affects the growth rate of films deposited using H2O. The growth rate of films deposited using O3, especially at growth temperatures < 300 °C, is extremely high, probably because of the hydrogen atoms existing in [(Me3Si)2N]3Lu.