Metal-insulator-metal capacitors using atomic-layer-deposited Al 2O3/HfO2/Al2O3 sandwiched dielectrics for wireless communications

Abstract

High density metal-insulator-metal (MIM) capacitors are required for radio frequency and analog/mixed-signal integration circuit applications. In this article, high permittivity Al2 O3 Hf O2 Al2 O3 (AHA) dielectrics have been evaluated in comparison with Hf O2 using atomic layer deposition technique for MIM capacitor applications. The results indicate that the AHA dielectrics exhibit electrical performance superior to the Hf O2 dielectric while retaining similar capacitance density. With respect to 2 nm individual Al2 O3 barriers, the MIM capacitor can offer a capacitance density of 2.6 fFμ m2, voltage coefficients of capacitance of 71 ppm V2 and 9 ppmV, a leakage current as low as 3× 10-9 A cm2 at 1 MVcm and 125 °C, an operating voltage of around 3 V for a ten-year lifetime at 125 °C in terms of 50% failure. © 2006 American Vacuum Society.