Plasma Enhanced Atomic Layer Deposition of Al2O3/SiO2 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 (αVCC) of Al
₂
O
₃
and the negative αVCC 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/μm
²
, a leakage current density of 6.8 nA/cm
²
at 1 V, and a minimized αVCC of -20 ppm/V
²
.