Premium
Ferroelectric La‐Doped ZrO 2 /Hf x Zr 1− x O 2 Bilayer Stacks with Enhanced Endurance
Author(s) -
Popovici Mihaela,
Walke Amey M.,
Banerjee Kaustuv,
Ronchi Nicolo,
Meersschaut Johan,
Celano Umberto,
McMitchell Sean,
Spampinato Valentina,
Franquet Alexis,
Favia Paola,
Swerts Johan,
Van den Bosch Geert,
Van Houdt Jan
Publication year - 2021
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.202100033
Subject(s) - materials science , orthorhombic crystal system , monoclinic crystal system , doping , ferroelectricity , hafnium , bilayer , tetragonal crystal system , phase (matter) , tin , analytical chemistry (journal) , layer (electronics) , zirconate , zirconium , crystallography , titanate , chemistry , optoelectronics , dielectric , crystal structure , metallurgy , nanotechnology , ceramic , biochemistry , organic chemistry , chromatography , membrane
Hafnium zirconate (HZO) is investigated in metal–ferroelectric–metal capacitors as a function of Hf/(Hf+Zr) atomic ratio, the presence of a thin ZrO 2 seed layer, and/or by doping HZO with La 3+ . It is demonstrated that a longer endurance is achieved with Hf‐rich HZO by introducing a ZrO 2 seed layer. The endurance is further improved by introducing La 3+ in the Hf‐rich HZO layer of the bilayer stack, which offers a higher 2 P r in the pristine state compared with a stoichiometric HZO doped with the same amount of La 3+ . Both ZrO 2 underlayer and La 3+ doping of HZO are shown to play a decisive role in promoting the formation of an orthorhombic and tetragonal phase at the expense of a detrimental monoclinic phase.