Crystallinity of Electrically Scaled Atomic Layer Deposited HfO2 from a Cyclical Deposition and Annealing Scheme

Abstract

In this work, we present structural characterization of HfO2 films deposited using a cyclical deposition and annealing scheme (termed DADA). Electrical performance improvements were obtained for atomic layer deposited (ALD) HfO2 films grown by use of this DADA process compared to a single deposition followed by a post-deposition anneal (PDA). In order to probe the structural characteristics of films deposited using this DADA process, in this study we utilized grazing incidence in-plane X-ray diffraction and pole figure measurements using synchrotron radiation as well as transmission electron microscopy. Structural differences were investigated from different annealing conditions as well as from different thickness of films. We observed significant differences in structural properties of DADA films compared to films receiving PDA. We also report on the evolution of monoclinic HfO2 with a (1̅11) preferred orientation (fiber texture) for DADA films whereas PDA treatment resulted in a random grain alignment and mixed phase structure.