Plasma Enhanced Atomic Layer Deposition of Al 2 O 3 /SiO 2 MIM Capacitors

Metal–insulator–insulator–metal (MIIM) capacitors with bilayers of Al 2 O 3 and SiO 2 are deposited at 200 °C via plasma enhanced atomic layer deposition. Employing the cancelling effect between the positive quadratic voltage coefficient of capacitance ( $\alpha $ VCC) of Al 2 O 3 and the negative $\alpha $ VCC of SiO 2 , devices are made that simultaneously meet the International Technology Roadmap for Semiconductors 2020 projections for capacitance density, leakage current density, and voltage nonlinearity. Optimized bilayer Al 2 O 3 /SiO 2 MIIM capacitors exhibit a capacitance density of 10.1 fF/ $\mu \text{m}^{2}$ , a leakage current density of 6.8 nA/cm $^{2}$ at 1 V, and a minimized $\alpha $ VCC of −20 ppm/ $\text{V}^{2}$ .