Ultra-thin poly-crystalline TiN films grown by HiPIMS on MgO(100) - In-situ resistance study of the initial stage of growth

The growth of ultra-thin TiN films on single-crystalline MgO(100) substrates by high power impulse magnetron sputtering (HiPIMS) was studied for growth temperatures ranging from 35 degrees C to 600 degrees C. X-ray analysis showed that the films had a textured poly-crystalline structure. Films grown by dc magnetron sputtering (dcMS) were epitaxial at the higher growth temperatures. In-situ resistance measurements, during growth, revealed the coalescence thickness and film continuity thickness. The film grown by HiPIMS at room temperature coalesced at 1.2 +/- 0.1 nm and became structurally continuous at 2.67 +/- 0.15 nm. At 600 degrees C, the coalescence and continuity thicknesses decreased to 0.56 +/- 0.05 nm and 0.82 +/- 0.05 nm, respectively. X-ray reflectivity measurements revealed that the growth rate of the films was roughly constant for all growth temperatures. The film density increased slightly with growth temperature up to 5.3 g/cm(3) at 600 degrees C and the surface roughness of the films decreased from 1 nm to 0.3 nm while the growth temperature increased from 35 degrees C to 600 degrees C. Grazing incident X-ray diffraction measurements showed the presence of [111], [200] and [220] crystallites at all growth temperatures. The smallest [200] and [220] grain sizes appeared at 100 degrees C while the [200] grain size increased by increasing the growth temperature. (C) 2013 Elsevier B.V. All rights reserved.