High permittivitty (La0.5Sr0.5)CoO3-δ-La(Co0.5Ti0.5)O3-δ ceramic composites for next generation MIM capacitors

Dielectrics with low capacitance loss and high relative permittivity are of high demand in metal-insulator-metal (MIM) capacitor that offers higher level of miniaturization, flexibility and performance. In order to achieve high relative permittivity, developing ceramics with metallic inclusions, has been suggested as a working strategy. But such materials may have high leakage currents and often lack thermal stability. With the objective for MIM applications, a series of (1-x)La(Co0.5Ti0.5)O3-δ-x(La0.5Sr0.5)CoO3-δ ceramics [x = 0.0, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2, 0.3, 0.4, 0.5, 1] were developed. The crystal structure analysis was performed for La(Co0.5Ti0.5)O3-δ, (La0.5Sr0.5)CoO3-δ and 0.5La(Co0.5Ti0.5)O3-δ-0.5(La0.5Sr0.5)CoO3-δ using X-pert High Score Plus. The composite with x = 0.5 in (1-x)La(Co0.5Ti0.5)O3-δ-x(La0.5Sr0.5)CoO3-δ showed a maximum relative permittivity of 4920 with promising ac electrical resistivity (∼202 Ω-cm). The thermal, electrical and dielectric properties together suggest that the composition 0.5La(Co0.5Ti0.5)O3-δ-0.5(La0.5Sr0.5)CoO3-δ is suitable for MIM capacitors in DRAM and RF devices.