High density metal-insulator-metal capacitor based on $ZrO2∕Al2O3∕ZrO2$ laminate dielectric

The metal-insulator-metal (MIM) capacitor for analog and rf applications has been developed with $ZrO2∕Al2O3∕ZrO2$ laminate as the dielectric. The high capacitance density of $21.54fF∕μm2$ can be achieved due to the tetragonal $ZrO2$ which makes the higher dielectric constant of 38.7. This MIM capacitor also demonstrates the quadratic voltage coefficient of $2443ppm∕V2$ and the good leakage current of $2.11×10−6A∕cm2$ at $2V$ which is ascribed to the inserted $Al2O3$⁠. Since the Schottky emission is suggested as the major dielectric conduction mechanism, a further reduced quadratic voltage coefficient and leakage characteristic can be realized by using a high work-function electrode. The combination of the promising electrical properties and the desirable process integration renders this structure highly suitable for advanced MIM capacitors.