Effects of annealing temperature on RF behaviour of Mg0.2Zn0.8O thin films

The preparation of Mg_0.2Zn_0.8O thin films using sol gel spin coating technique is described. The films will be used as an alternative dielectric material for monolithic microwave integrated circuit (MMIC). In this work, the samples were annealed at various temperatures in order to investigate the effect on the film structure and radio frequency (RF) properties. X-Ray Diffractometer (XRD) was used to analyze the film crystallinity. It was found that the crystallinity of the films improve with higher annealing temperatures. In order to study the RF properties, capacitors with 50 × 50 μm² electrode area were patterned on the MgZnO layer using electron beam lithography (EBL). RF measurements were conducted using wafer probes over the frequency range of 0.5 to 3 GHz. Our findings show that there are significant effects on the RF behavior for different annealing temperatures. The measured results at 1 GHz of the return loss, dielectric constant, capacitance and loss tangent reveals that the RF performance improves with higher annealing temperatures. Our films show lowest loss tan measured for these films at microwave frequencies.