Engineering of interfacial layer between HfAl 2O 5 dielectric film and Si with a Ti-capping layer

Abstract

HfAl 2O 5 dielectric film with an O-gettering Ti-capping layer was treated with rapid thermal annealing process and its interfacial structure and surface morphology were reported. X-ray reflectivity measurements and X-ray photoelectron spectroscopy indicated that the interfacial layers were composed of a 0.5 nm HfAlSiO layer and a 1.5 nm Si x (SiO 2) 1 − x ( x < 1) layer for the as-deposited film. However, for the annealed film, HfAlSiO layer was not found and the 1.5 nm Si x (SiO 2) 1 − x transformed to a 1 nm SiO 2. Atom force microscopy showed that a Ti-capping layer did not affect surface roughness.