Texturing and Tetragonal Phase Stabilization of ALD Hf_xZr_(1-x)O_2 using a Cyclical Deposition and Annealing Scheme

摘要

In order to enhance the dielectric properties of HfO_2, the alloying of HfO_2 with ZrO_2 was studied. Hf_xZr_(1-x)O_2 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 ZrO_2 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 Hf_xZr_(1-x)O_2 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 Hf_xZr_(1-x)O_2 films with higher Zr content grown by DADA in contrast to random orientation in post deposition annealed films.