In this brief, we reported the improved break- down reliability and endurance in 10-nm Hf _0.5 Zr _0.5 O ₂ (HZO) using grain boundary interruption. By inserting an amorphous Al ₂ O ₃ layer in the middle of polycrystalline HZO, grain boundaries penetrating between the electrodes were interrupted. Compared with single-layer HZO [metal-ferroelectric-metal (MFM)] and HZO/Al ₂ O ₃ [metal-ferroelectric-insulator-metal (MFIM)], the ferroelectric/insulator/ferroelectric [metal-ferroelectric-insulator-ferroelectric-metal (MFIFM)] structure exhibited $9\times $ reduction of leakage current, 0.85-V increase of breakdown (BD) voltage ( ${T}_{\text {BD}}$ ), and 0.97-V increase of voltage for 10-year time-dependent dielectric breakdown (TDDB) lifetime. Furthermore, >10 ¹⁰ endurance was achieved in MFIFM capacitor, which has more than three orders of magnitude improvement than MFM and MFIM capacitor. This work provides an effective way to enhance the reliability of HZO-based ferroelectric devices.

In this letter, the endurance performance of the TiN/Hf _0.5 Zr _0.5 O ₂ (HZO)/TiN ferroelectric capacitor is significantly improved by increasing the N content of the TiN top electrode. The gas with different N ₂ flow is used in the top TiN electrode sputter process. Compared to N-deficient capacitor, the leakage current density of the N-rich capacitor is reduced by sixfold (from $1.7\,\,\times10$ ⁻⁵ $\text{A}/$ cm ² to $9.2\,\,\times10$ ⁻⁶ $\text{A}/$ cm ² ), the dielectric constant is increased correspondingly. The endurance is improved by three orders of magnitude (from 10 ⁶ to over $3\,\,\times10$ ⁹ at 3 V read voltage) because of the addition of more N ₂ flow. And it enhances breakdown voltage and the TDDB reliability. The reduction in defects (especially oxygen-vacancies) near the interface in the N-rich capacitor is responsible for the improvement.

In this letter, NH ₃ plasma treatment was utilized to improve the ferroelectric property of widely used TiN/Hf _x Zr _y O ₂ (HZO)/TiN capacitors. The developed metal-ferroelectric-metal (MFM) structure shows high remnant polarization (P _r ) of $30 ~\mu \text{C}$ /cm ² after 10-min NH ₃ treatment at bottom TiN electrode. Materials characterization were subject to investigate the behind mechanism. A higher ferroelectric o-phase formation in NH ₃ -treated HZO device is revealed by grazing incidence X-ray diffraction (GIXRD). In addition, the high-resolution transmission electron microscopy (HRTEM) indicates that the NH ₃ treatment optimizes the interface quality by restraining of the interfacial layer (IL) including intrinsic TiO _x N _y dead-layer and non-ferroelectric layer. Furthermore, the improved interface engineering also suppressed the imprint effect, which prompts the retention improvement of TiN/Hf _x Zr _y O ₂ /TiN ferroelectric capacitors.

Flexible memory devices are promising for information storage and data processing applications in portable, wearable, and smart electronics operating under curved conditions. In this work, we realized high-performance flexible ferroelectric capacitors based on Hf_0.5Zr_0.5O₂ (HZO) thin film by depositing a buffer layer of Al₂O₃ on polyimide (PI) substrates using atomic layer deposition (ALD). The flexible ferroelectric HZO films exhibit high remnant polarization (P_r) of 21 µC/cm². Furthermore, deterioration of polarization, retention, and endurance performance was not observed even at a bending radius of 2 mm after 5,000 bending cycles. This work marks a critical step in the development of high-performance flexible HfO₂-based ferroelectric memories for next-generation wearable electronic devices.

In this letter, sub-10-nm air channel devices were fabricated with the aid of photolithography and focused ion beam (FIB) etching. Field emission (FE) properties of the device were measured under ambient conditions. The operation mechanism was discussed by means of current-voltage (I-V) curve fitting and energy band diagram analysis. On account of the extremely shrinking of nano-gap, record-high emission currents of 355.6 μA at 1 V were realized in air with a threshold voltage as low as 0.588 V. A cycle test of 200 times was also performed to verify and analyze the stability of the device. Importantly, the temporal response performance of the device was also measured. It demonstrated a high-speed and repeatable output waveform with a rise/fall time of ~ 100 ns. This study demonstrates a practical nano-fabrication technology to fabricate sub-10-nm air channel devices with ultra-low operating voltage, which can be utilized as an electrical element in high-speed and low-power integrated circuits.

It is widely believed that the fatigue process of ferroelectric HfZrO (HZO) film is a permanent damage and unrecoverable, which can be regarded as a Time Dependent Dielectric Breakdown (TDDB) process. In this work, the fatigue process of HZO film under low-electric field is found to be irrelevant to defect generation. Furthermore, this fatigued device can be recovered by higher voltage stimulus and then switch normally with lower voltage pulses. This observed recoverable fatigue process is systematically investigated by the conductance method and the first-order reversal curve (FORC) measurement and the mechanism is attributed to electron de-trapping. This observed recoverable fatigue process gives the new insights on the endurance failure mechanism of HZO film under low-electric field.