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We report a stacked Y2O3/TiO x resistive random access memory (RRAM) device, showing good high-temperature switching characteristics of extremely low reset current of 1 μA at 150 °C, large off/on resistance window (>200) at 150 °C, large rectification ratio of ∼300 at 150 °C and good current distribution at 85 °C. The good rectifying property, lower high-temperature sneak current and tighter high-temperature current distribution can be attributed to the combined results of the oxygen vacancies in TiO x and the related carrier depletion effect. [ABSTRACT FROM AUTHOR]

In this study, we report a low power Ni/GeO x /TiO y /TaN resistive random access memory (RRAM) using plasma-modified electrode. The low sub-mA switching current, highly uniform switching cycles (only 4% variation for the set) and good high-temperature current distribution at 125 °C are simultaneously achieved in this RRAM device. Such good performance can be ascribed to interface plasma treatment on TaN electrode where the resulting Ta-N ionic bond increases the oxidation resistance and reduces the oxygen vacancy concentration near TaN interface that is favorable to lower switching power and improve high-temperature current distribution. [ABSTRACT FROM AUTHOR]

In this Letter, we report a low operation voltage and high mobility flexible InGaZnO thin-film transistor (TFT) using room-temperature processed Y2O3/TiO2/Y2O3 gate dielectric. The flexible IGZO TFT showed a low threshold voltage of 0.75 V, a small sub-threshold swing of 137 mV/decade, a good field effect mobility of 32.7 cm2/V s, and a large Ion/ Ioff ratio of 1.7 × 106. The low operation voltage, small sub-threshold swing and high mobility could be ascribed to the combination of high- κ TiO2 and large band gap Y2O3, which provide the potential to meet the requirements of low-temperature and low-power portable electronics. [ABSTRACT FROM AUTHOR]

Power consumption is the most difficult challenge for CMOS integrated circuits. Here, we demonstrate experimentally a novel steep turn-on pMOSFET for low-voltage operation for the first time, which exhibits 5–60 mV/decade SS, wide voltage range for SS<60~mV/decade, sturdy <60~mV/decade SS at 85^\circC, faster transistor turn-on at above threshold voltage, and lower off-state leakage by greater than three orders of magnitude. Such improved leakage current is crucial to decrease the off -state leakage current in sub-1X nm CMOS. This was achieved using ferroelectric high-\kappa ZrHfO gate dielectric pMOSFET. [ABSTRACT FROM AUTHOR]

In this work, it is demonstrated that the negative capacitance effect of ferroelectric Hf1−xZrxO2 transistor is highly correlated with Zr doping concentration. A steep subthreshold swing of 40 mV/decade, a low off‐state leakage current of 190 fA μm−1, and a large on/off current ratio of >107 can be simultaneously achieved in optimized negative capacitance Hf1−xZrxO2 transistor. Besides, the Zr diffusion issue and non‐ferroelectric phases significantly affect the multi‐domain switching of polycrystalline Hf1−xZrxO2. Therefore, an appropriate amount of Zr substitution is more favorable for both boosting ferroelectric and implementing the negative capacitance switch. [ABSTRACT FROM AUTHOR]

A ferroelectric negative‐capacitance (NC) transistor using aluminum‐doped hafnium oxide (HfAlOx) with fluorine passivation is successfully demonstrated. The fluorine‐passivated device shows a nearly hysteresis‐free forward/reverse swing of sub‐30 mV dec−1 for symmetric switch, a wide sub‐60 mV (dec·swing)−1 range over 4 decades of drain current, an ultralow off‐leakage current of 4 fA μm−1, and a high on/off current ratio of >108. The fluorine defect passivation (FP) reduces oxygen vacancies of ferroelectric HfAlOx to mitigate interface depolarization field and thereby reinforce surface potential amplification effect during NC operation. The authors successfully demonstrate a ferroelectric negative‐capacitance (NC) transistor using HfAlOx with fluorine passivation, which exhibits a nearly hysteresis‐free sub‐30 mV dec−1 swing for symmetric switch, a wide sub‐60 mV (dec·swing)−1 range over 4 decades of drain current, and an ultralow off‐leakage current. The defect passivation reduces oxygen vacancy of ferroelectric HfAlOx to mitigate interface depolarization field and thereby reinforce the NC effect. [ABSTRACT FROM AUTHOR]

The effect of Ta2O5 doping on electrical characteristics of SrTiO3 (STO) metal–insulator–metal (MIM) capacitors was studied for the first time. Using Ta2O5-doped STO dielectrics, an absolute quadratic voltage coefficient of capacitance (VCC-α) of 510 ppm/V2 and a high capacitance density of ∼20 fF/µm2 are achieved. These are approximately one order of magnitude lower than those of the MIM capacitor fabricated using a pure STO. In addition, the degradation of electrical properties (capacitance variation versus voltage, VCC-α, and long-term reliability) after electrical stressing is reduced, compared with that of an MIM capacitor fabricated using a pure STO. [ABSTRACT FROM AUTHOR]

TiO 2 /ZnO films grown by atomic layer deposition (ALD) demonstrated nanotribological behaviors using scratch testing. TEM profiles obtained an amorphous structure TiO 2 and nanocrystalline structure ZnO, whereas the sample has significant interface between the TiO 2 /ZnO films. The experimental results show the relative XRD peak intensities are mainly contributed by a wurtzite oxide ZnO structure and no signal from the amorphous TiO 2 . With respect to tribology, increased friction causes plastic deformation between the TiO 2 and ZnO films, in addition to delamination and particle loosening. The plastic deformation caused by adhesion and/or cohesion failure is reflected in the nanoscratch traces. The pile-up events at a loading penetration of 30 nm were measured at 21.8 μN for RT, 22.4 μN for 300 °C, and 36 μN for 400 °C. In comparison to the other conditions, the TiO 2 /ZnO films annealed at 400 °C exhibited higher scratch resistance and friction with large debris, indicating the wear volume is reduced with increased annealing temperature and loading. [ABSTRACT FROM AUTHOR]

Abstract: We used atomic layer deposition to form ZnO thin-film coatings on Si substrates and then evaluate the effect of pile-up using the nanoscratch technique under a ramped mode. The wear volume decreased with increasing annealing temperature from room temperature to 400°C for a given load. Elastic-to-plastic deformation occurred during sliding scratch processing between the groove and film for loading penetration of 30nm. The onset of non-elastic behavior and greater contact pressure were evident for loading penetration of 150nm; thus, full plastic deformation occurred as a result of a substrate effect. We suspect that elastic–plastic failure events were related to edge bulging between the groove and film, with elastic–plastic deformation attributable to adhesion discontinuities and/or cohesion failure of the ZnO films. [Copyright &y& Elsevier]

Highlights: [•] IGZO TFT with GeO2/TiO2/GeO2 dielectric has been fabricated on PC substrate at room temperature. [•] RT Flexible TFT exhibits small gate swing of 0.132V/decade and good Ion/Ioff ratio of 2.4×107. [•] Such good performance was attributed to combined effect of higher-κ TiO2 and large band gap GeO2. [ABSTRACT FROM AUTHOR]

Abstract: We report a room-temperature and high-mobility InGaZnO thin-film transistor on flexible substrate. To gain both high gate capacitance and low leakage current, we adopt stacked dielectric of Y2O3/TiO2/Y2O3. This flexible IGZO TFT shows a low threshold voltage of 0.45 V, a small sub-threshold swing of 0.16 V/decade and very high field-effect mobility of 40 cm2/V. Such good performance is mainly contributed by improved gate stack structure and thickness modulation of IGZO channel that reduce the interface trap density without apparent mobility degradation. [Copyright &y& Elsevier]

• Nanoscale ferroelectric domain switching of undoped HfO 2 were investigated. • Well-controlled thermal stress can enhance polarization strength of undoped HfO 2. • Ferroelectric negative capacitance effect can be improved by thickness scaling. • Undoped HfO 2 NCFET with tight hysteresis distribution can be achieved. In this work, we investigated the polarization characteristics of nanoscale undoped hafnium oxide (HfO 2) ferroelectric film. The nanoscale domain switching behavior of undoped HfO 2 is mainly dominated by mixed ferroelectric/nonferroelectric crystalline phases and interface domain pinning by oxygen vacancies or defect traps. Our experimental results confirm that these issues can be improved by film thickness scaling and well-controlled mechanical stress. We demonstrated a 4-nm-thick undoped HfO 2 negative capacitance thin film transistor (NCFET) with an energy-efficient switch characteristic of a low overdrive voltage of -0.6 V, a steep subthreshold swing of sub-60 mV/dec and a uniform hysteresis distribution of sub-60 mV. [ABSTRACT FROM AUTHOR]

In this study, the plasma oxidation effect in tin-oxide (SnOx) thin film was investigated. And on this basis, we fabricated n-type thin-film transistors (TFTs) using the SnOx thin film with the plasma oxidation by experiments. By adjusting the processing time of the oxygen plasma treatment (OPT), the optimized SnOx TFT device exhibited an extremely high field-effect mobility of 87.6 cm2 V−1 s−1, a desirable on-to-off current ratio of 1.9 × 104 and a threshold voltage of − 0.9 V. Furthermore, we investigated the origin of the performance enhancements in the n-type SnOx TFTs with the optimized OPT by introducing the density of states (DOS) modeling in TCAD simulation. The numerical simulation indicated that the attributes of donor-like Gaussian defect states (oxygen vacancies) were modified in overall DOS due to the plasma oxidation effect. These present results show that the SnOx TFT treated by oxygen plasma has great promise in the future high-performance flat panel display industries. [ABSTRACT FROM AUTHOR]

In this work, we successfully demonstrated the 9.6-nm-thick HfAlO x ferroelectric memory using light aluminium doping of 6.5% to form ferroelectric orthorhombic phase. Compared to ferroelectric HfZrO x film with zirconium diffusion issue, the HfAlO x film showed excellent thermal stability under high temperature annealing. Besides, the ferroelectric HfAlO x also exhibited robust polarization characteristics under endurance cycling test. A >106 stressed cycles with 4 MV/cm can be measured and a long endurance was sustained over 5 × 107 cycles under 3.6 MV/cm. Therefore, the HfAlO x film showed the great promise for integrating in high performance ferroelectric memory with thermal budget concerns. • Thermal stability, dynamic leakage issue and endurance of HfO 2 -based memory were investigated. • Less amount of aluminum doping into HfO 2 was favorable to reduce dynamic leakage during ferroelectric switching. • A long and stable endurance can be sustained over 5 × 107 cycles under 3.6 MV/cm in HfAlO x memory. • Thermally-stable HfAlO x memory showed the potential for the integration with modern gate-first CMOS process. [ABSTRACT FROM AUTHOR]

An experiment was carried out to investigate the influence of CaCO 3 and SiO 2 additives on the magnetic and physical properties of M-type Sr ferrites by changing experimental parameters such as the additive composition and Ca/Si ratio. Specimens were prepared by conventional ceramic techniques. It was found that the magnetic properties (B r  = 4.42 kG, iH c  = 3.32 kOe and (BH) max  = 4.863 MGOe) were considerably improved upon adding CaCO 3  = 1.1% and SiO 2  = 0.4 wt% together with Co 3 O 4 , and the mechanical properties thereof were acceptable for motor applications. It was revealed that CaCO 3 and SiO 2 additives led to an upswing in the magnetic properties via the enhancement of uniform grain growth, particle alignment, and the densification of Sr ferrite. [ABSTRACT FROM AUTHOR]