Plasma Enhanced Atomic Layer Deposition of Al2O3/SiO2 MIM Capacitors

Metal-insulator-insulator-metal (MIIM) capacitors with bilayers of Al2O3 and SiO2 are deposited at 200 degrees C via plasma enhanced atomic layer deposition. Employing the cancelling effect between the positive quadratic voltage coefficient of capacitance (alpha VCC) of Al2O3 and the negative alpha VCC of SiO2, 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 Al2O3/SiO2 MIIM capacitors exhibit a capacitance density of 10.1 fF/mu m(2), a leakage current density of 6.8 nA/cm(2) at 1 V, and a minimized alpha VCC of -20 ppm/V-2.