Crystallization annealing effects on ferroelectric properties of Al-Doped HfO2 thin film capacitors using indium–tin–oxide electrodes

Electrical properties of yttrium-doped hafnium-zirconium dioxide thin films prepared by solution process for ferroelectric gate insulator TFT application

“…Oxide top electrode such as RuO 2 and ITO for HfO 2 -based ferroelectric materials were deposited by sputtering in the previous reports. [43][44][45] Here, we used CSD ITO films as top electrode. Hence, the samples here are fabricated by all solution process as reported for PZT films previously.…”

“…Ryu et al reported lower P r value with ITO as compared to Pt top electrode, but it is worth noting that ITO top electrode shows better endurance as compared to Pt due to suppressing the generation of excessive oxygen vacancies at the top interfaces. 44) Next, we evaluated the C-V characteristics to check the ferroelectric nature of the Y-HZO films. Figures 6(b), 6(d), and 6(f) show C-V curves of ITO/Y-HZO MFS structures, depicting clear butterfly shape with capacitance maxima on negative voltage side around E C value, whereas large decrease on the positive voltage side is observed, which is due to depletion of ITO top electrode.…”

Fabrication Strategies of Metal–Ferroelectric–Insulator–Silicon Gate Stacks Using Ferroelectric Hf–Zr–O and High-k HfO2 Insulator Layers for Securing Robust Ferroelectric Memory Characteristics

“…Ferroelectric field-effect transistors (FeFETs) utilizing HfO 2 -based ferroelectrics have attracted considerable attention as one of the promising advanced nonvolatile memory devices (NVMs) due to their prospective advantages such as excellent compatibility with complementary metal oxide semiconductor (CMOS) technology, low operation voltage, and fast program/erase speeds. − Synaptic devices and steep-slope negative capacitance transistors can also be implemented by modulating the gate stack structures of the FeFETs. − These novel device functions are based on the ferroelectric nature of the HfO 2 -based thin films, which are initiated by the formation of a polar orthorhombic phase ( o -phase) with a noncentrosymmetric space group Pca 2 1 . , However, a ferroelectric o -phase should be stabilized by various additional methodologies such as doping process, strain engineering, and film thickness control. − In particular, for the doping process, the incorporation of cation dopants with smaller ionic radius than Hf ion into the HfO 2 crystal lattices facilitates the phase transformation from the tetragonal phase ( t -phase) to o -phase . Although excellent ferroelectricity of Al-doped HfO 2 (Al/HfO 2 ) or Si-doped HfO 2 (Si/HfO 2 ) thin films has previously been demonstrated, sophisticated process conditions were required to be established for the employment of these dopants owing to the narrow process margins in terms of annealing conditions and interfacial strain for securing the outstanding ferroelectric behaviors. , Alternatively, Hf 1– x Zr x O 2 (HZO) ferroelectrics have been featured to have wide process margins without the additional incorporation of interfacial strain for various ferroelectric device applications. , …”

“…11−15 These novel device functions are based on the ferroelectric nature of the HfO 2 -based thin films, which are initiated by the formation of a polar orthorhombic phase (o-phase) with a noncentrosymmetric space group Pca2 1 . 16,17 However, a ferroelectric o-phase should be stabilized by various additional methodologies such as doping process, strain engineering, and film thickness control. 18−20 In particular, for the doping process, the incorporation of cation dopants with smaller ionic radius than Hf ion into the HfO 2 crystal lattices facilitates the phase transformation from the tetragonal phase (t-phase) to ophase.…”

Preventing Color Fading in Artist’s Oil Paintings Based on Nano-PZT Ferroelectric Thin Film

“…Since photo-oxidation aging plays an important role in the fading of oil paintings, researchers are trying to add light stabilizers to oil paintings to delay the fading of oil paintings. According to the mechanism of action, light stabilizers can be divided into shielding agents, ultraviolet absorbers, quenchers, and free radical scavengers (mainly inhibitory amine derivatives) [13,14]. At present, the major research in foreign countries is UV absorbers.…”