Texturing and Tetragonal Phase Stabilization of ALD HfxZr1-xO2 Using a Cyclical Deposition and Annealing Scheme

Abstract

In order to enhance the dielectric properties of HfO2, the alloying of HfO2 with ZrO2 was studied. HfxZr1-xO2 films with different Hf:Zr ratios were deposited by atomic layer deposition (ALD) combined with a cyclical deposition and annealing scheme (termed DADA) in which an annealing was performed after every 20 ALD cycles. The impact of the ZrO2 addition on the structural properties of the ALD grown films was investigated by grazing incidence in-plane X-ray diffraction and pole figure measurement using synchrotron radiation as well as transmission electron microscopy and X-ray photoelectron spectroscopy. The HfxZr1-xO2 films with x=1 show the presence of monoclinic (-111) fiber texture. As the Zr content increases, stabilization of the tetragonal phase is observed. The pole figure measurements indicate the presence of tetragonal (111) fiber texture for the ALD HfxZr1-xO2 films with higher Zr content grown by DADA in contrast to random orientation in post deposition annealed films.