Microstructure analysis of thin films deposited by reactive evaporation and by reactive ion plating

Electron microscopy, stylus-type surface profilometry, and Raman microprobe characterization show distinct differences between thin films deposited by reactive evaporation and by reactive ion plating. Reactive evaporation yields thin films with the well-known columnar microstructure with appreciable surface roughness and other deficiencies. Low-voltage, high-current reactive ion plating deposition produces thin films which are smooth and dense. Cross-section electron micrographs of ion plated coatings reveal a densely packed polycrystalline structure for ZrO2 , while TiO2 appears to form vitreous films. Molecular dynamics computer simulation of the film formation process is in good qualitative agreement with the experiments. The results suggest the expansion of the Movchan--Demchishin structure zone model with an additional zone 4 for the vitreous phase, resulting from superthermal film formation conditions (thermal spiking)