Xi-ming Chen

Local Piezoelectric Properties and Polarity Distribution of ZnO Films Deposited at Different Substrate Temperatures

In this work we deposited c-axis-oriented ZnO films using radiofrequency magnetron sputtering at substrate temperatures from 200°C to 500°C. We then characterized their local piezoelectric properties and polarity distributions using piezoresponse force microscopy, revealing that these ZnO films contained grains with opposite polarities: O-face and Zn-face. The grains with O-face polarity exhibited larger piezoresponse magnitude than those with Zn-face polarity. As the substrate temperature was increased, the predominant polarization orientation of the films changed from O-face to Zn-face. The film deposited at 300°C showed uniform polarization orientation together with higher piezoresponse magnitude.