Investigation on the Electric Properties of $\hbox {Bi}_{1.5}\hbox {ZnNb}_{1.5}\hbox {O}_{7}$ Thin Films Grown on TiN Substrate for MIM Capacitors

A small crystalline phase was formed in the Bi_1.5ZnNb_1.5O₇ (BZN) film grown at 300degC on TiN/SiO₂/Si substrate using RF-magnetron sputtering. A 46-nm-thick BZN film exhibited a high capacitance density of 13.6 fF/mum² at 100 kHz with a dielectric constant of 71, which did not change even in the gigahertz range (1-6 GHz). The quality factor was high, approximately 50, at 2.5 GHz. The leakage-current density was low, approximately 5.66 nA/cm², at 2 V. The quadratic voltage and temperature coefficients of capacitance were approximately 631 ppm/V² and 149 ppm/degC at 100 kHz, respectively. These results indicate that the BZN film grown on TiN substrate at 300degC can be a good candidate material for metal-insulator- metal capacitors.