Microstructural improvement of sputtered ZrO₂ thin films by substrate biasing

We have fabricated zirconia (ZrO₂) thin films on Si(1 0 0) wafers that possess excellent crystallinity and orientation. Furthermore, the interfacial properties between the thin films and Si substrate have been improved by means of substrate biasing. The influence of the substrate bias on the interfacial and microstructural characteristics of the ZrO₂ thin films has been investigated in details. Our results show that by applying a suitable bias to the Si substrate, the microstructure of ZrO₂ thin films becomes more ordered and the interfacial by-products can be suppressed. The effects and mechanism of the bias on the microstructure of the thin films are described.