Atomic Layer Deposited High‐κ Films and Their Role in Metal‐Insulator‐Metal Capacitors for Si RF/Analog Integrated Circuit Applications

Abstract

Abstract In this paper, we present an extensive evaluation of metal‐insulator‐metal (MIM) capacitors by comparing various high‐κ dielectric structures based on atomic layer deposited HfO 2 and Al 2 O 3 films at two thicknesses. The results indicate that laminate‐structured MIM capacitors provide superior performance to their sandwiched/stacked counterparts in both thin (∼13 nm) and thick (∼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 Al 2 O 3 into bulk HfO 2 , thereby preventing crystallization of HfO 2 .