Effect of Ta₂O₅ doping on electrical characteristics of SrTiO₃ metal-insulator-metal capacitors

The effect of Ta₂O5 doping on electrical characteristics of SrTiO₃ (STO) metal-insulator-metal (MIM) capacitors was studied for the first time. Using Ta₂O₅-doped STO dielectrics, an absolute quadratic voltage coefficient of capacitance (VCC-α) of 510ppm/V² and a high capacitance density of ̃20fF/μm ² are achieved. These are approximately one order of magnitude lower than those of the MIM capacitor fabricated using a pure STO. In addition, the degradation of electrical properties (capacitance variation versus voltage, VCC-α, and longterm reliability) after electrical stressing is reduced, compared with that of an MIM capacitor fabricated using a pure STO.