Monitoring the microstructure of nanosized palladium layers obtained via thermal and VUV stimulated MOCVD

Nanosized palladium layers on silicon (100) substrates were obtained employing MOCVD method under VUV and thermal stimulations in hydrogen medium, with the use of Pd(hfaс)2 as a precursor. The deposition temperature under thermal stimulation amounted to 230 °C, whereas with the VUV (145 nm) stimulation this value was equal to 100 °C, within the time interval ranging from 1 to 30 min. With the use of monochromatic null ellipsometry and scanning electron microscopy techniques, initial stages of palladium nanolayer growth were studied. It has been established that the growth of Pd films exhibits a pronounced cyclical character. The analysis of electron microscopy images of growing film surfaces was based on the Voronoi–Delaunay method with the introduction of parameters such as peak, valley and minimum spanning tree (MST). It was demonstrated that the parameters used directly reflect the process of film growth, whereby two stages of the process have been distinguished.