Composition and electrical characteristics of Al2O3-HfO2-HfTiO nanolaminates on Si

A dielectric constant of 27 was demonstrated in the as deposited state of a 5 nm thick, seven layer nanolaminate stack comprising Al2O3, HfO2 and HfTiO. It reduces to an effective dielectric constant (k(eff)) of similar to 14 due to a similar to 0.8 nm interfacial layer. This results in a quantum mechanical effective oxide thickness (EOT) of similar to 1.15 nm. After annealing at 950 degrees C in an oxygen atmosphere k(eff) reduces to similar to 10 and EOT increases to 1.91 nm. A small leakage current density of about 8 x 10(-7) and 1 x 10(-4) A/cm(2). respectively at electric field 2 and 5 MV/cm and a breakdown electric field of about 11.5 MV/cm was achieved after annealing at 950 degrees C. (C) 2008 Elsevier B.V. All rights reserved.