Electrical properties of (Zr,Ti)0.85(Ca,Sr)0.15O1.85 thin film grown on Pt/Ti/SiO2/Si substrate using RF magnetron sputtering

Crystalline (Zr,Ti)0.85(Ca,Sr)0.15O1.85 (ZTCS) films were grown on a Pt/Ti/SiO2/Si substrate at various temperatures by using rf-magnetron sputtering. The ZTCS films had a cubic stabilized zirconia structure. The dielectric constant (k) of the ZTCS film grown at 300 °C was approximately 30.5 with a low tan δ value of 0.007 at 100 kHz. Further, this film exhibited a similar k value of 30.4 and a high quality factor of 225 at 1.0 GHz. Moreover, it showed a high capacitance density of 290 nF/cm2 with a small TCC of −60.7 ppm/°C at 100 kHz. A low leakage current (1.4×10−8 A/cm2 at 1.5 MV/cm) with a high breakdown electric field (1.85 MV/cm) was also observed in this film; the leakage current of this film was explained by Schottky emission. Therefore, it can be concluded that ZTCS films grown at low temperatures (≤300 °C) are good candidates for use as embedded capacitor in printed circuit boards.