Effect of deposition interruption and substrate bias on the structure of sputter-deposited yttria-stabilized zirconia thin films

The possibility of altering the morphological structure of radio-frequency magnetron sputter- deposited yttria-stabilized zirconia thin films was studied. A columnar grain structure is often observed in sputter deposited thin films; however, this morphology may not be desirable. Two potential methods of disrupting the columnar grain structure were investigated; deposition interruption and periodic application of a substrate bias. Simple interruption of the deposition process was not effective in altering the columnar grain structure of the sputter-deposited films. The use of a periodic substrate bias produced a laminate structure with alternating layers of distinctly different microstructure. X-ray diffraction showed that as the thickness of the layers decreased (with increasing number of layers), the monoclinic phase was eliminated from the deposited thin films, and the films showed a preference for the $(200)t$ orientation.