Influence of oxygen source on the ferroelectric properties of ALD grown Hf_1-xZr_xO₂ films

Hafnium oxide (HfO₂), zirconium oxide (ZrO₂), and the solid-solution (Hf_1-xZr_xO₂) system continue to be some of the most relevant ferroelectric materials, in particular, for their promising application in CMOS integrated ferroelectric memories. Recent understanding of the influence of oxygen supplied during film deposition on the structural phase formation process in Hf_1-xZr_xO₂ films has drawn attention to a commonly overlooked parameter for tuning ferroelectric and electrical properties of these films. In this paper, a comparison of O₃ and O₂ plasma used as the oxygen source in an atomic layer deposition process for Hf_1-xZr_xO₂ films within the full compositional range is discussed. A combination of structural and electrical characterization methods grant insight on the influence of each of the oxygen sources on the crystalline phase formation during deposition of Hf_1-xZr_xO₂ films. These observations are then correlated to the material's behavior regarding its ferroelectric and electrical properties; mainly, dielectric constant, ferroelectric remanent polarization, and number of electric field cycles to breakdown. (paper)