Effects of Mg doping content and annealing temperature on the structural properties of Zn_(1-x)Mg_xO thin films prepared by radio-frequency magnetron sputtering

The doping content of Mg plays an important role in the crystalline structure and morphology properties of Zn_(1-x )Mg_xO thin films. Here,using radio-frequency magnetron sputtering method,we prepared Zn_(1-x )Mg_xO thin films on single crystalline Si(100) substrates with a series of x values. By means of X-ray diffraction(XRD) and scanning electron microscope(SEM),the crystalline structure and morphology of Zn_(1-x )Mg_xO thin films with different x values are investigated. The crystalline structure of Zn_(1-x )Mg_xO thin film is single phase with x<0.3,while there is phase separation phenomenon with x>0.3,and hexagonal and cubic structures will coexist in Zn_(1-x )Mg_xO thin films with higher x values. Especially with lower x values,a shoulder peak of 35.1° appearing in the XRD pattern indicates a double-crystalline structure of Zn_(1-x )Mg_xO thin film. The crystalline quality has been improved and the inner stress has been released,after the Zn_(1-x )Mg_xO thin films were annealed at 600 °C in vacuum condition.