Stabilizing the ferroelectric phase in HfO₂-based films sputtered from ceramic targets under ambient oxygen

Abstract

Thin film metal-insulator-metal capacitors with undoped hafnium oxide and the mixture of hafnium and zirconium oxide are fabricated by sputtering from ceramic targets. The influence of the oxygen concentration in...

Aging in Ferroelectric Si‐Doped Hafnium Oxide Thin Films

“…A similar approach is used to achieve ferroelectricity in doped HfO 2 manufactured by physical vapor deposition (PVD), where grain‐size control allows the stabilization of the polar orthorhombic phase. [ 19 ] A schematic cross‐section of the manufactured pyroelectric structures is shown in Figure a, where the Si substrate, TiN electrodes, HfO 2 layers, and Al 2 O 3 separator are indicated. X‐ray reflectometry (XRR) measurements are carried out to confirm the film thickness.…”

Interplay between oxygen defects and dopants: effect on structure and performance of HfO2-based ferroelectrics

“…A similar sample set was analysed by Mittmann et al, 55 this time for sputtered Hf x Zr 1−x O 2 layers. Again, increased oxygen flows encouraged the stabilization of the monoclinic phase.…”

Temperature‐Dependent Phase Transitions in HfxZr1‐xO2 Mixed Oxides: Indications of a Proper Ferroelectric Material

“…[ 7 ] Depending on dopant and oxygen vacancy content in the film, the nonpolar tetragonal (t) or the ferroelectric orthorhombic (o) phase can be found. [ 8,9 ] For high oxygen content/oxygen interstitials, activation barriers for a transition from the t‐ to the o‐phase prevent the phase change and the monoclinic (m) phase can be formed. Accordingly, dopant and oxygen vacancy content are two main causes of ferroelectric phase formation in this material system.…”