The Electrical Performances and Leakage Current Conduction Mechanism of Al2O3/ZrO2/SiO2/ZrO2/Al2O3 MIM Capacitors

In this paper, we prepared the Al2O3/ZrO2/SiO2/ZrO2/Al2O3 (AZSZA) metal-insulator-metal (MIM) capacitors by atomic-layer-deposition technique. By increasing the thickness of SiO2 from 0 nm to 3 nm, the quadratic capacitance voltage coefficients improved significantly from 2130 ppm/V-2 to -121 ppm/V-2 because of the offsetting effects of ZrO2 and SiO2 dielectric. Meanwhile, for our interested SiO2=3nm sample, the capacitance density is 7.40 fF/mu m(2) and the leakage current density is 3.08 x 10(-8) A/cm(2) at 5 V. We also studied the leakage current conduction mechanism of AZSZA dielectric MIM capacitors and found that at high field the conduction mechanism was dominated by Poole Frenkel emission.

Automated summary

The AZSZA metal-insulator-metal (MIM) capacitors prepared by atomic-layer-deposition technique showed improved quadratic capacitance voltage coefficients when the thickness of SiO2 was increased. The leakage current density was low for the SiO2=3nm sample, and the conduction mechanism at high field was dominated by Poole Frenkel emission.