Thin Solid Films, Vol.519, No.10, 3358-3362, 2011
Ni-Al-O diffusion barrier layer for high-kappa metal-oxide-semiconductor capacitor
Using amorphous Ni-AI-O (a-Ni-AI-O) thin film as the intermediate layer, poly-crystalline Er203 thin film was grown on a-Ni-AI-O/Si (p-type) via laser molecular beam epitaxy, forming the Er(2)O(3)/Ni-AI-O gate stack. It was found that the mean dielectric constant of the Er(2)O(3)/Ni-AI-O gate stack with an equivalent oxide thickness of 1.5 nm is about 17-23, the interfacial states density is about 3.16 x 10(12) cm(-2) and the stack gate leakage current density is as small as 4.1 x 10(-6) A/cm(2). Furthermore, The insertion of the Ni-AI-O thin film between the Er(2)O(3) gate dielectric and p-Si substrate prevents the oxygen from being out-diffused, which significantly improved the stability of gate stack, showing that the Er(2)O(3)/Ni-Al-O gate stack thin film could be used as an ideal gate oxide layer for the future Metal Oxide Semiconductor Field Effect Transistors. (C) 2010 Elsevier B.V. All rights reserved.