Journal of Vacuum Science & Technology B, Vol.17, No.4, 1464-1469, 1999
Study of crystal orientation in Cu film on TiN layered structures
The effect of underlayer texture on Cu film orientation has been studied. Cu texture correlates well with the underlayer texture. The Cu(111) crystallographic orientation is enhanced on TiN film with a strong TiN(111) orientation. Cu preferred orientation can be controlled by choosing an appropriate underlayer. Cross-sectional transmission electron microscope observation revealed that the Cu(111) plane grows epitaxially on the TiN(111) plane in spite of the large lattice mismatch between Cu and TiN. The atomic arrangement between Cu(111) and TiN(111) planes in TiN film deposited on Cu film has a rotational angle within +/- 10 degrees around the (111) axis. On the other hand, in Cu film deposited on TIN film, there are two rotational angles: a rotational angle of 25 degrees-30 degrees in large Cu grain region and little rotation with rotational angle distributions less than 100 in a small Cu grain region. These results can be explained by consideration of superlattice mismatch. Cu(111) plane rotation occurs so as to have more energy stable position at coalescence stage.