Epitaxial growth of (1 1 1)ZrN thin films on (1 1 1)Si substrate by reactive sputtering and their surface morphologies

We have investigated the epitaxial growth of (1 1 1)ZrN films on (1 1 1)Si substrate at a relatively low temperature using an ultrahigh vacuum DC magnetron sputtering system. The film quality obtained and the epitaxial relationship were evaluated on the basis of analyses of X-ray diffraction (XRD) patterns, X-ray pole figures, and grazing incidence angle X-ray reflectivity (GIXR), transmission electron microscopy (TEM) and atomic force microscopy (AFM) results. It was found that (1 1 1)ZrN films were grown epitaxially on (1 1 1)Si at a substrate temperature of 500∘C with the directional relationship ZrN(1 1 1)[1 1 0] ∥∥ Si(1 1 1)[1 1 0]. GIXR and AFM results also revealed that the epitaxial (1 1 1)ZrN film has a high film density comparable to that of bulk ZrN and a fairly flat surface morphology with an average surface roughness of approximately 0.25 nm.