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A simplified one-diode one-resistor (1D1R) resistive switching memory cell that uses only four layers of TaN/ZrTiO/Ni/n-Si was proposed to suppress sneak current where TaN/ZrTiO/Ni can be regarded as a resistive-switching random access memory (RRAM) device while Ni/n-Si acts as an Schottky diode. This is the first RRAM cell structure that employs metal/semiconductor Schottky diode for current rectifying. The 1D1R cell exhibits bipolar switching behavior with SET/RESET voltage close to 1 V without requiring a forming process. More importantly, the cell shows tight resistance distribution for different states, significantly rectifying characteristics with forward/reverse current ratio higher than 10 and a resistance ratio larger than 10 between two states. Furthermore, the cell also displays desirable reliability performance in terms of long data retention time of up to 10 s and robust endurance of 10 cycles. Based on the promising characteristics, the four-layer 1D1R structure holds the great potential for next-generation nonvolatile memory technology. [ABSTRACT FROM AUTHOR]

Highlights: [•] Orthorhombic ZrTiO4 and amorphous Yb2O3 were confirmed by XRD and TEM. [•] Gate stack of ZrTiO4/Yb2O3 shows low D it and a small fixed oxide charge density. [•] MOSFETs with 0.79-nm EOT and excellent sub-Vt swing of 66mV/dec were realized. [•] Good reliability is proven by negligible ΔVt, Δgm and sub-Vt swing degradation. [Copyright &y& Elsevier]

Highlights: [•] Investigate the impact of dielectric crystallinity on the performance of RRAM. [•] Provides more insights into the different conduction mechanisms for RRAM operation. [•] Amorphous ZrTiO x outperforms crystalline ZrTiO x for RRAM applications. [Copyright &y& Elsevier]

Diffusion of deuterated poly(methylmethacrylate) (dPMMA) is sloweddown in a PMMA matrix filled with hydroxyl-capped spherical silicananoparticles, from 13 to 50 nm in diameter and at loadings up to40 vol %. At constant T– Tg= 75 K, the normalized diffusion coefficients (D/D0) collapse onto a mastercurve, when plotted against the confinement parameter, ID/2Rg, where IDis interparticledistance and 2Rgis probe size. This resultsuggests that the confinement parameter captures the effect of nanoparticlesize, size polydispersity, and volume fraction on polymer dynamicsfor the PMMA composite. For ID< 2Rg, the master curve exhibits a strongly confined regionwhere D/D0decreasesby up to 80%, whereas for ID> 2Rg, the curve falls in a weakly confined region where D/D0decreasesonly moderately by up to 15%. Surprisingly, D/D0is reduced even when IDis8 times larger than 2Rg. A comparisonbetween the master curves for PMMA and polystyrene nanocompositesindicates that attractive interactions in the PMMA system do not significantlyalter the center-of-mass diffusion of macromolecules in polymer nanocomposites. [ABSTRACT FROM AUTHOR]

An amorphous (ZrO_2) _x(La _2O_3) 1-x alloy formed by depositing a ZrO _2/La_2O _3/ZrO_2 laminate and a subsequent annealing was employed as the gate dielectric for metal-oxide-semiconductor (MOS) devices. The (ZrO_2) _x(La_2O_3)1-x alloy is found to have a high permittivity κ of 26.2 with negligible amount of bulk traps, both of which are very desirable for advanced gate dielectrics. By integrating the (ZrO_2)_x(La _2O_3) 1-x alloy with an SiON interfacial layer as the gate stack, it displays good frequency dispersion in capacitance–voltage (C –V) characteristics and low interfacial trap density of 1.52 × 10^11 cm^-2 eV^-1. In addition, the current conduction mechanism of the gate stack is observed to be Fowler–Nordheim tunneling and the leakage current of 3.6 × 10^-6 A/cm^2 at the gate voltage of −1 V for equivalent oxide thickness of 1.1 nm can be achieved, which is superior to other high-κ dielectrics. Furthermore, satisfactory reliability is verified by bias temperature instability measurement. Most importantly, this gate stack not only exhibits a promising perspective for advanced CMOS technology but introduces a more reliable process to form an alloy-based high-κ gate dielectric. [ABSTRACT FROM PUBLISHER]

High entropy oxides (HEOx) are novel materials, which increase the potential application in the fields of energy and catalysis. However, a series of HEOx is too novel to evaluate the synthesis properties, including formation and fundamental properties. Combining first-principles calculations with machine learning (ML) techniques, we predict the lattice constants and formation energies of spinel-structured photocatalytic HEOx, (Co,Cr,Fe,Mn,Ni)3O4, for stoichiometric and non-stoichiometric structures. The effects of site occupation by different metal cations in the spinel structure are obtained through first-principles calculations and ML predictions. Our predicted results show that the lattice constants of these spinel-structured oxides are composition-dependent and that the formation energies of those oxides containing Cr atoms are low. The computing time and computing energy can be greatly economized through the tandem approach of first-principles calculations and ML. [ABSTRACT FROM AUTHOR]

Ge MOS devices passivated by SmGeOx with equivalent oxide thickness of 0.61 nm were employed as the platform to evaluate the eligibility of SmGeOx as Ge surface passivation layer. The SmGeOx layer was formed by deposition of Sm2O3 on Ge substrate with a subsequent O2 annealing and the formation of SmGeOx was confirmed by X-ray photoelectron spectroscopy. The tiny frequency dispersion in capacitance measurement and a low interface trap density of 5.1\times 10^11~cm^-2eV^-1 near midgap attest to desirable passivation effect and it can be ascribed to Sm-Ge-O bonding, which is favorable in mitigating dangling bonds at Ge surface. In addition, the small hysteresis in capacitance also suggests good quality of bulk dielectric. Due to the small amount of bulk traps and large conduction band offset with respect to Ge, it enjoys low leakage current of 0.36 A/cm^2 at gate bias of Vfb (flatband voltage)-1 V. Through the test of bias temperature instability, the passivation layer demonstrates reasonable reliability performance in terms of 65-mV flatband voltage shift at 85^\circC after stressing with -16~MV/cm for 1000 s. With these characteristics, SmGeOx is promising as a passivation layer for aggressively scaled Ge MOS devices. [ABSTRACT FROM AUTHOR]

TaN/ZrTiOx/Pt metal-insulator-metal structure was employed as the platform to evaluate the eligibility for antifuse one-time programmable (OTP) memory applications, and the impact of O2 plasma on device performance was also discussed. Owing to the oxygen radicals that enhance the dielectric integrity, the voltage for state switching increases with O2 plasma treatment. Memory cells without plasma treatment demonstrate promising characteristics for OTP memory applications in terms of a low dc switching voltage of 2 V, high programming speed of 60 ns, high read endurance up to 10^6 reading cycles, and desirable retention time and low switching power density of 6.4 mW/cm^2. The memory cell technology not only exhibits the prominent performance which is advantageous over other dielectrics reported in the literature, but it also possesses the capability to from stackable 3-D architecture. [ABSTRACT FROM PUBLISHER]

Perovskite-based BaZry\rm Ti1-y\rm O3 (BZTO) (y=0.6) with partial crystallization has been found to possess a rather high-\kappa value of 48.6 and positive quadratic voltage coefficient of capacitance (VCC). Through stacking BZTO and ZrTiOx as laminate dielectric, metal–insulator–metal capacitors using VCC canceling effect advance frontiers by exhibiting a record-low VCC of 14 ppm/V^2 at the capacitance of 13.4 fF/\mum^2, low dielectric loss tangent <0.01, and low leakage current of 7.5\times 10^-9~A/cm^2 at -1~V. With constant voltage stress at 2.5 V for 1000 s, degradation in leakage current <30\% is observed. In addition, excellent reliability of 0.89% capacitance change against stress up to a projected of 10 years is also achieved. The aforementioned characteristics not only compare favorably to other high-\kappa-based dielectrics, most importantly, but also these results meet ITRS requirements set by 2024. [ABSTRACT FROM AUTHOR]

In this letter, ZrLaOx/\rm ZrTiOx/ZrLaOx laminate is employed as the platform for investigating the effects of plasma nitridation on the electrical performance and reliability of metal–insulator–metal capacitors. After plasma nitridation of ZrTiOx, the capacitance density and quadratic voltage coefficient of capacitance (VCC-\alpha) degraded slightly to 14.38 fF/\mum^2 and 68 ppm/V^2. These results meet the International Technology Roadmap for Semiconductors requirements for implementation in 2020. The major benefits of plasma nitridation are the enhanced performance of the electrical characteristics and reliability. The process reduces leakage current by a factor of 32.8, and improves stress-induced leakage current by a factor of 10.6. In addition, near frequency-independent capacitance is achieved after stressing at 2.5 V for 1000 s, and a desirable reliability of 0.27% capacitance change after a 10-year operation under 2.5-V stress is attained. These results suggest that nitrided ZrTiOx enables ZrLaOx/\rm ZrTiOx/ZrLaOx laminate to be a candidate for use in advanced circuit applications. [ABSTRACT FROM PUBLISHER]

Metal–insulator–metal (MIM) capacitors with \ZrLaOx \/ZrTiOx\/ZrLaOx laminate as the insulator were explored in this work. Single \ZrTiOx dielectric was found to have a negative quadratic voltage coefficient of capacitance (VCC-\alpha) with a high \kappa value of 22.5. By integrating this dielectric with \ZrLaOx which provides a positive VCC- \alpha and a high \kappa value of 25.8, the “canceling effect” of VCC- \alpha can be achieved while a high capacitance density can be maintained. MIM capacitors with the laminated structure display desirable characteristics in terms of a capacitance density of 14.6 \fF/\mu\m^2, a low VCC- \alpha of 33 \ppm/V^2, negligible frequency dispersion, and satisfactory leakage current of \1.6 \times \10^-6\ \A/cm^2 at -1.5 V. These results also well meet the International Technology Roadmap for Semiconductors requirement set for 2020. [ABSTRACT FROM AUTHOR]