Atomic layer deposited high-kappa films and their role in metal-insulator-metal capacitors for Si RF/analog integrated circuit applications

Abstract

In this paper, we present an extensive evaluation of metal-insulator-metal (MIM) capacitors by comparing various high-K dielectric structures based on atomic layer deposited HfO2 and Al2O3 films at two thicknesses. The results indicate that laminate-structured MINI capacitors provide Superior performance to their sandwiched/stacked counterparts in both thin (similar to 13 nm) and thick (similar to 55 nm) dielectric films. Benefits include low leakage current, good polarity-independent electrical characteristics, high-breakdown electrical field (voltage), and long time-to-breakdown while maintaining comparable capacitance density and voltage coefficients of capacitance. It is noted, however, that the benefits of the laminate structure become less significant when the dielectric thickness decreases. The advantages of the laminate structure are mainly attributed to the alternate insertions of Al2O3 into bulk HfO2, thereby preventing crystallization of HfO2.