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Understanding species boundaries maintenance in the face of hybridization/introgression is an intriguing yet complex topic in evolutionary biology. The underlying mechanisms, however, remain elusive. To address this, we propose to investigate the role of climatic shifts in shaping genetic structure and influencing species boundaries. We combine multilocus genetic data and species distribution modeling to explore how past and current climatic shifts affect the genetic structure and demographic history of two Taiwan endemic gingers, Zingiber pleiostachyum and Z. shuanglongense. We identified a well-delimited genetic structure with evidence of admixture, indicating incomplete reproductive isolation between the two gingers. This is likely due to secondary contact and range overlap during the last glacial maximum, leading to sporadic instances of hybridization. Niche overlap tests based on climate and soil data indicate that these two gingers occupy similar but nonidentical ecological niches. Furthermore, we found that the considerable differences in their current geographic distribution and altitude preferences might have resulted from different seed dispersal capabilities and competitive exclusion due to their similar niche preferences. Our results reveal a model where altitudinal differentiation and dispersal strategy synergistically reinforce the species divergence, thereby illuminating the importance of these factors in shaping and maintaining the island's biodiversity. [ABSTRACT FROM AUTHOR]

Aim: The Massenerhebung effect (Mass elevation effect) refers to heat‐ or wind‐driven altitudinal distribution patterns of temperature‐dependent parameters among massifs with narrower range and lower elevation around peripheral and isolated mountains compared to core and continuous ones. Although common in ecology, this effect is rarely discussed in population genetics. Here, we use genetic markers to reveal population genetic patterns and also test the mountain‐ and sky‐barrier hypotheses relevant to the Massenerhebung distribution pattern of Acer morrisonense in Taiwan's rugged topography and varied local climates. Location: The alpine and cloud forest of Taiwan. Taxon: Acer morrisonense Hayata. Methods: Two chloroplast DNA (cpDNA) fragments and 17 expressed sequence tag‐simple sequence repeat (EST‐SSR) loci, respectively, from 200 to 286 individuals were used to elucidate the phylogeographic pattern of pollen and seed dispersal of A. morrisonense. These data were combined with ecological niche modeling (ENM) to infer distribution range shifts and refugia. We also correlated the genetic‐divergence indices with spatial factors to clarify latitudinal and altitudinal effects on genetic diversity. Results: The incongruent phylogeographic patterns of genetic distributions between nuclear and cpDNA markers indicate unhindered pollen flow but spatially constrained seed dispersal. Taken together with ENM, the genetic pattern further reflects historical colonization from central‐mountain refugia to edges since the Holocene. The Massenerhebung reduces the gene flow by the surrounding mountains and also causes lower genetic diversity compared to central alpine populations. Main conclusions: This study is the first to reveal the influence of Massenerhebung effect on cpDNA genetic structure of montane trees and reflect the spatial trends of seed dispersal. This population genetic pattern can also be attributed to the demography‐related range shifts with paleoclimate fluctuations under complex mountain topography, supporting the mountain‐barrier hypothesis. The results have important implications for conserving the genetic diversity of species with a wide altitudinal distribution range. [ABSTRACT FROM AUTHOR]

In this work, we systematically investigate the effects of the insertion of the solid-state electrolyte material copper–tellurium (CuTe) in resistance random access memory (RRAM). The CuTe layer is inserted as Cu/CuTe/SiO2/TiN (top-to-bottom) and the device exhibits excellent resistance switching (RS) characteristics such as lower forming bias, a larger memory window and faster RS speed, compared to the Cu/SiO2/TiN device. This validates the effects of the inserted CuTe layer with a Cu electrode. Furthermore, an additionally fabricated Cu/CuTe/TiN device demonstrates that the CuTe layer can also successfully act as a middle insulator for the RRAM device, based on the obtained experimental results. [ABSTRACT FROM AUTHOR]

In this study, vanadium (V) was used as a top electrode in a vanadium oxide (VOx)-based selector device. Electroforming was performed to form a threshold region with metal–insulator transition (MIT) at both V electrode and VOx switching layers without annealing during fabrication. The simple V/VOx/TiN structure obtained was scalable and compatible with complementary metal–oxide–semiconductors. All electrical measurement results indicated that V/VOx/TiN selectors exhibited excellent characteristics such as high uniformity, a short switching time of 60 ns, a robust endurance of >109 cycles, and high reliability and stability. Both the simulation analysis and current fitting method were applied to further validate experimental results. Consequently, we developed a nanoscale V/VOx/TiN selector with excellent characteristics, which can be potentially applied to future highdensity crossbar memory devices to overcome sneak-path problems. [ABSTRACT FROM AUTHOR]

In this work, capacitance-voltage (C–V) measurement and analysis were performed on silicon (Si)-based devices at low temperature (77 K). By this method, the C–V curves were compared for two devices with channel materials of Si and silicon–germanium (SiGe). The lattice mismatch of SiGe results in more defects at the interface between the channel and the gate insulator layer, which cause abnormal C–V properties. Through comprehensive theoretical calculation, proved by Silvaco simulation, an energy band diagram and physical model are proposed. Furthermore, the distribution of donor-like states can be examined, which can assist in monitoring the interface quality. [ABSTRACT FROM AUTHOR]

HfZrOx (HZO)-based materials have received much attention due to their special film characteristics in recent years. Ferroelectric random access memory (FeRAM) based on this HZO material also has promising potential as a next generation memory due to its non-volatile characteristics, excellent endurance, and low power consumption. Previous research has mainly focused on the material properties of HZO-based FeRAM. However, an in-depth investigation of the electrical properties of HZO-based FeRAM is necessary to better understand its transporting mechanism. In this contribution, this study aims to investigate the mechanism of an HZO-based metal–ferroelectric-metal capacitor using comprehensive experimental results, including current–voltage, capacitance–voltage, and polarization–voltage measurements. Experiments at various temperatures are also conducted to help verify the transport mechanism. The low current transport by the Fowler–Nordheim tunneling mechanism does not change with temperature, whereas the high current transport via the Schottky mechanism increases with increasing temperature. We found that the orientation of the dipole plays an important role. Finally, we also propose a band model to explain the electron transport in this HZO-based FeRAM. [ABSTRACT FROM AUTHOR]

This study examines the influence of different electrode thermal conductivity on switching behavior during the reset process. Electrical analysis methods and an analysis of current conduction mechanism indicate that better thermal conductivity in the electrode will require larger input power in order to induce more active oxygen ions to take part in the reset process. More active oxygen ions result in a more oxidized switching layer, and cause the effective switching gap (dsw) to become larger in the reset process. The effect of the electrode thermal conductivity and input power are explained by our model and clarified by electrical analysis methods. [ABSTRACT FROM AUTHOR]

In this letter, the electrical characteristics of Ti/HfO2/TiN resistive random access memory (RRAM) were thoroughly investigated. An abnormal current degradation was seen in the DC sweeping cycle. Both the on-state and off-state current clearly exhibited degradation with time. Next, current fitting analysis was used to investigate the carrier transport mechanisms. The results indicate that the on-state carrier transport mechanism changed from space-charge-limited current into hopping conduction after cycle sweeping. However, the off-state current changes from Schottky thermal emission to hopping conduction. Based on comparisons of different Schottky distances and Schottky barriers, physical models were proposed to explain the abnormal current degradation behavior. Finally, COMSOL electric field simulations were used to show the electric field distribution around the conducting filament (CF), and the conducting model was subsequently verified. [ABSTRACT FROM AUTHOR]

This letter investigates Au30Ag70 (alloy electrode)/SiO2/TiN conductive-bridge random access memory (CBRAM) to verify the influence of ambient conditions on forming voltage ($\text{V}_{\textsf {F}}$) and the location of galvanic reaction. Previous literature demonstrates that the galvanic reaction in CBRAM with an alloy electrode results in a lower $\text{V}_{\textsf {F}}$. In this work, a higher environmental H2O concentration results in a decrease in $\text{V}_{\textsf {F}}$. From this change in $\text{V}_{\textsf {F}}$ , we infer that environmental H2O concentration influences the amount of galvanic reaction. Moreover, we verify the location of the galvanic reaction by varying electrode thickness. Finally, we propose a physical model to explain our observations. [ABSTRACT FROM AUTHOR]

By varying the forming process to a constant voltage sampling forming mode, the Pt/GeTeOx/TiN memory device exhibited analog properties, and continuous multilevel conductance states were obtained through applying appropriate pulse sequences. These characteristics were exploited to demonstrate spike-timing-dependent plasticity learning, indicating that the device had great potential not only in non-volatile digital systems but also in neuromorphic computing systems. Moreover, the conduction mechanism of the device with different forming modes was investigated. [ABSTRACT FROM AUTHOR]

Abstract The white Spot Syndrome Virus (WSSV) is a pathogen that causes huge economic losses in the shrimp-farming industry globally. At the WSSV genome replication stage (12 hpi) in WSSV-infected shrimp hemocytes, activation of the PI3K-Akt-mTOR pathway triggers metabolic changes that resemble the Warburg effect. In shrimp, the upstream regulators of this pathway are still unknown, and in the present study, we isolate, characterize and investigate two candidate factors, i.e. the shrimp Ras GTPase isoforms LvRas and LvRap, both of which are upregulated after WSSV infection. dsRNA silencing experiments show that virus replication is significantly reduced when expression of either of these genes is suppressed. Pretreatment with the Ras inhibitor Salirasib further suggests that LvRas, which is a homolog to a commonly overexpressed human oncoprotein, may be involved in regulating the WSSV-induced Warburg effect. We also show that while both the PI3K-Akt-mTOR and Raf-MEK-ERK pathways are activated by WSSV infection, LvRas appears to be involved only in the regulation of the mTOR pathway. Highlights • Both LvRas and LvRap were isolated and characterized from white shrimp (Litopenaeus vannamei). • In vivo knockdown by RNA interference suggests that LvRas and LvRap are both is important for WSSV replication. • In vivo suppression of LvRas with the inhibitor Salirasib further suggests its involvement in WSSV replication. • LvRas activation is critical for the WSSV-induced Warburg effect. • LvRas activation activates the PI3K-mTOR pathway, but not the ERK pathway. [ABSTRACT FROM AUTHOR]

In this paper, vanadium oxide (VOx) was chosen for the resistive switching layer in a typical resistive random access memory (RRAM) structure. During negative forming bias, we found an initial selector property. This indicates the presence of metal–insulator-transition characteristics in the VOx layer even without an annealing process. In order to study this phenomenon, material analyses were conducted, with results indicating that there are V-O stretching bonds and an oxide/vanadium ratio of nearly 2.2 (${O}/{V} = {2.2}$). In addition, the experimental results of the dc sweeping test indicated that off-state current gradually decreased after each cycle, meaning that the selectivity characteristics in the VOx selector could be improved. Endurance performance of our experimental devices reached 108, sufficient for integration with RRAM devices in a 1S1R array. To further investigate this special phenomenon, current fitting analysis and simulation analyses were conducted. The results of the fitting analysis indicated that the conduction mechanism for off-state current was Schottky emission and the Schottky distance increased with increasing numbers of cycles. In other words, oxide ions migrate toward the filament at low negative voltage during dc sweeping, causing the formation of VOx. Furthermore, the results of thermal field simulation analysis indicated that there is a thermal concentration effect in and around the filament. Thus, oxide ions more easily migrate toward the vanadium filament when a stronger electrical field is present around the filament during dc sweeping cycles. Finally, stable vanadium selector characteristics are obtained and a conduction filament behavior model is proposed. [ABSTRACT FROM AUTHOR]

In this study, an Ag-Cu alloy was chosen as the electrode in conductive bridging random access memory (CBRAM), with results indicating a significant decrease in forming voltage. In addition, resistive switching characteristics as well as a retention test indicated better stability and a resistive switching window of at least an order. The switching time of the Ag-Cu alloy CBRAM is shorter than that of both Ag and Cu electrode CBRAMs under fast current-voltage (fast I-V). The experimental result indicated that the mechanism was dominated by the galvanic effect. Active atoms (Ag) captured electrons of inactive atoms (Cu) and generated metallic ions (Cu ions) in the alloy electrode. Cu ions drifted into the insulator and generated a conductive path when applying voltage bias. The use of this alloy as an electrode in CBRAM can significantly decrease forming voltage and enhance CBRAM characteristics. [ABSTRACT FROM AUTHOR]

This letter introduces a method of using bipolarity bias voltages in the forming process to effectively reduce the forming voltage of a one-transistor and one-resistance random access memory device. A bipolar incremental-step-pulse programming process is applied, and a complete operation pulse for the forming process is described. This method reduces forming voltage without any cost to the device performance, and the device maintains good reliability. The likely physical mechanism of this bipolar operation is also presented based on the measured electrical characteristics. [ABSTRACT FROM PUBLISHER]

A nitridation treatment technology with a urea/ammonia complex nitrogen source improved resistive switching property in HfO-based resistive random access memory (RRAM). The nitridation treatment produced a high performance and reliable device which results in superior endurance (more than 10 cycles) and a self-compliance effect. Thus, the current conduction mechanism changed due to defect passivation by nitrogen atoms in the HfO thin film. At a high resistance state (HRS), it transferred to Schottky emission from Poole-Frenkel in HfO-based RRAM. At low resistance state (LRS), the current conduction mechanism was space charge limited current (SCLC) after the nitridation treatment, which suggests that the nitrogen atoms form Hf-N-Ox vacancy clusters (V ) which limit electron movement through the switching layer. [ABSTRACT FROM AUTHOR]

In this study, the rising forming voltage issue during device cell scale-down in resistance random access memory (RRAM) is solved by introducing new high-permittivity (high- k) material as the side-wall spacer structure, unlike the normally used low-permittivity (low- k) material. Simulated electrical fields based on COMSOL Multiphysics software results suggest a RRAM device with a high- k spacer effectively confines the electric field. The effects of this confined electric field are notable, especially when the device cell is scaled down. The device fabrication process is modified to incorporate the high- k sidewall. Cross-sectional transmission electron microscopy imaging confirms the existence of SiO2 and HfO2 as the spacer structures in two different devices. Electrical measurements of forming voltages ranging from 1 to 0.16 µm2 are conducted to verify the effects. Statistical measurements confirm that the forming voltages of the devices with high- k material as sidewall do not increase with a reduction in device cell size. Moreover, reliability tests, including endurance and retention for the high- k sidewall device, also exhibit very stable resistance switching characteristics. As a result, the structure that is proposed successfully solves the forming voltage issues within small device cells in RRAM without any cost to device reliability. [ABSTRACT FROM AUTHOR]

This paper investigates the characteristics of applying indium–tin oxide (ITO) with and without nitride gas (N2) as the insulator in resistive random access memory (RRAM). After cosputtering an ITO target with N2 as the insulator and capping the same ITO material as the top electrode, the device exhibits rectifier and resistance switching characteristics before and after the forming process, respectively. The Schottky diodelike rectifier mechanism was also verified by various temperature measurements. Furthermore, robust resistance switching at a positive forming voltage, smaller than that required during negative bias forming, can be achieved. Both positive and negative forming processes are examined with current fitting results, which show different dominant mechanisms when using positive or negative biases. All these mechanisms have also been verified by temperature effect experiments, which confirmed the dominant conduction mechanisms. This, in combination with the fact that the positive forming voltage itself is smaller than the negative forming voltage, and decreases with device scale down, provides two highly beneficial results. This good performance achieved by using ITO with N2 suggests significant progress of RRAM and remarkable potential applications. [ABSTRACT FROM PUBLISHER]

A lower switching voltage of indium–tin–oxide (ITO)-based resistance random access memory (RRAM) with an inserted SiO2 thin film was presented. The amplitude of switching voltage of device was below 0.2 V whether measured by direct current or alternating current sweep operation. Notably, the observed reset voltage increased with temperature. To clarify the switching mechanism, conduction current fitting and switching voltage statistics were applied to explore the regular voltage variation dependent on temperature. In addition, a reaction model was proposed to explain the oxygen concentration gradient induced between the inserted SiO2 and ITO electrode on the ITO-based RRAM device. [ABSTRACT FROM PUBLISHER]

This letter investigates the double-ended resistive switching characteristics of indium tin oxide (ITO) resistance random access memory (RRAM). Resistive switching can be achieved around both the active TiN electrode and the inert Pt electrode. In addition, complementary resistance switching (CRS) characteristics can be observed without current compliance during dc voltage sweep operations. Electrical measurement data fitting results indicate that the oxygen-rich ITO near top and bottom electrodes works as a double-ended resistive switching layer. Based on the analysis of the current conduction mechanism, we propose a physical model to interpret the CRS behaviors in ITO RRAM devices. [ABSTRACT FROM AUTHOR]

Hybridization frequently occurs in plant species. With repeated backcross, the introgression may influence evolutionary trajectories through the entry of foreign genes. However, the genetic admixture via hybridization events is often confused with the ancestral polymorphism, especially in closely related species that have experienced similar evolutionary events. In Taiwan, two independent-originated endemic snakebark maples have contrasted postglacial range expansion routes: northward and upward expansion in Acer caudatifolium and downward expansion in A. morrisonense. The range expansion causes the current parapatric distribution, increasing the possibility of introgression. This study elucidates how their genetic variation reflects introgression and historical demography. With 17 EST-SSR markers among the intensely sampled 657 individuals, we confirmed that the genetic admixture between species mainly was attributed to recent introgression instead of common ancestral polymorphism. The secondary contact scenario inferred by approximate Bayesian computation suggested that A. morrisonense received more genetic variations from A. caudatifolium. Introgression occurred in colonized Taiwan around the early Last Glacial Period. Furthermore, the demography of A. caudatifolium was more severely affected by introgression than A. morrisonense, especially in the wavefront populations with high altitude range expansion, implying an altitude-related adaptive introgression. In contrast, A. morrisonense exhibited ubiquitous introgression independent of postglacial expansion, suggesting that introgression in A. morrisonense was neutral. In terms of different genetic consequences, introgression had different demographic impacts on species with different altitude expansion directions even under the same climate-change conditions within an island. [ABSTRACT FROM AUTHOR]

During an early epoch of development, the brain is highly adaptive to the stimulus environment. Exposing young animals to a particular tone, for example, leads to an enlarged representation of that tone in primary auditory cortex. While the neural effects of simple tonal environments are well characterized, the principles that guide plasticity in more complex acoustic environments remain unclear. In addition, very little is known about the perceptual consequences of early experience-induced plasticity. To address these questions, we reared juvenile rats in complex multitone environments that differed in terms of the higher-order conditional probabilities between sounds. We found that the development of primary cortical acoustic representations, as well as frequency discrimination ability in adult animals, were shaped by the higher-order stimulus statistics of the early acoustic environment. Our results suggest that early experience-dependent cortical reorganization may mediate perceptual changes through statistical learning of the sensory input. [ABSTRACT FROM AUTHOR]

In lieu of limited land resources, the improvement of land utilization has become an urgent issue and the concept of shortening the distance of "fire barriers" has been introduced accordingly. This study, based on the principle of improving fire performance, has developed blinds that can be applied to the openings of exterior walls and are environmentally friendly as well as feature energy saving, safety, and security characteristics. Moreover, they comply with the relevant "fire barriers" regulations in the Building Technical Rules. As shown in the experiments, the general type of blinds are made of 2 mm thick iron window frame and slats and coated with 800 μm thick fire retardant paint; during the one-hour fire resistance tests, the maximum radiant heat at the distance of 0.50 m, 1.00 m, and 2.50 m to the fire source is respectively 0.264 W/cm2, 0.207 W/cm2, and 0.080 W/cm2. The maximum environmental temperature of the distance of 1.00 m and 2.5 m to the fire source is 50.8°C and 35.7°C at greater distance and lower temperature than that of flammable limits, 1 W/cm2 and 260°C. [ABSTRACT FROM AUTHOR]

The statistical figures of Government showed, by the end of 2006, there were 13,579,885 motorcycles registered in Taiwan. Most of people in Taiwan are used to parking the motorcycles around buildings and the motorcycles are made of multifarious plastic materials (such as ABS, PP, PC, PU, PMMA, PA, etc.). Therefore, there were heavy casualties and property losses when motorcycle fires occurred. For research concerning motorcycles' combustion characteristics, the data is obtained via Cone Calorimeter, video recording, and other apparatuses. According to the experiment results, a full-scale motorcycle combustion, for which the fire growth model is α t2, the maximum heat release rate is about 1.106 MW, the fire decline model is a - b x ln (t + c), the average of flame height is 3.5 m, and the maximum temperature is 870.9°C. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide (SCCO2) fluid technology was applied to indium-tin-oxide (ITO) electrode to improve the resistive switching characteristic of silicon oxide RRAM through hydride oxidation for the first time. We found device power consumption can be effectively reduced so that side effects can be also restricted under device operation. By applying SCCO2 fluid, more oxygen ions will be introduced into the ITO electrode and thus the participation of net oxygen ions in the RRAM redox reaction will increase. Fourier transform spectroscopy and X-ray photoelectron spectroscopy were used to confirm hydride oxidation on ITO electrode. Combined with the current fitting results, we proposed a reaction model to explain the improvement of resistive switching in RRAM by SCCO2 fluids. [ABSTRACT FROM AUTHOR]

We have previously investigated the automatic current compliance property for indium tin oxide (ITO) resistance random access memory (RRAM). Traditionally, for the purpose of protecting RRAM, it is necessary to set equipment current compliance during the set and forming processes of RRAM devices. ITO RRAM devices, however, have an intrinsic capability to limit their current. This letter examines this ITO RRAM current compliance in depth by applying a varied stop-voltage measurement method, where different negative stop voltages were adopted to manipulate oxygen ions. Combined with material analysis and conduction current fitting, a model was established. [ABSTRACT FROM AUTHOR]

The manipulation of temperature coefficient of resistance (TCR) in TaN thin-film resistor (TFR) was demonstrated by electrical measurement and analysis through supercritical carbon dioxide (SCCO2 fluid treatment for the first time. The negative TCR value of TaN TFR changes to positive TCR value through annealing process due to the growth and merge of TaNx grain. After SCCO2 treatment, the positive TCR value was changed back to negative TCR value in TaN TFR. The TaN grain boundary isolated by dehydroxyl effect of SCCO2 fluid treatment causes the current conduction mechanism changed to hopping conduction from ohmic conduction. [ABSTRACT FROM AUTHOR]

A new root canal sealer was developed based on urethane acrylates using polycarbonate polyol (PCPO), a macrodiol prepared in the consumption of carbon dioxide as feedstock. The superior mechanical properties and biostability nature of PCPO-based urethane acrylates were then co-crosslinked with a difunctional monomer of tripropylene glycol diarylate (TPGDA) as sealers for resin matrix. Moreover, nanoscale silicate platelets (NSPs) immobilized with silver nanoparticles (AgNPs) and/or zinc oxide nanoparticles (ZnONPs) were introduced to enhance the antibacterial effect for the sealers. The biocompatibility and the antibacterial effect were investigated by Alamar blue assay and LDH assay. In addition, the antibacterial efficiency was performed by using Enterococcus faecalis (E. faecalis) as microbial response evaluation. These results demonstrate that the PCPO-based urethane acrylates with 50 ppm of both AgNP and ZnONP immobilized on silicate platelets, i.e., Ag/ZnO@NSP, exhibited great potential as an antibacterial composite for the sealer of root canal obturation. [ABSTRACT FROM AUTHOR]

The seasonal pollen index (SPI) is a continuing concern within the fields of aerobiology, ecology, botany, and epidemiology. The SPI of anemophilous trees, which varies substantially from year to year, reflects the flowering intensity. This intensity is regulated by two factors: weather conditions during flower formation and the inner resource for assimilation. A deterministic approach has to date been employed for predicting SPI, in which the forecast is made entirely by parameters. However, given the complexity of the masting mechanism (which has intrinsic stochastic properties), few attempts have been made to apply a stochastic model that considers the inter-annual SPI variation as a stochastic process. We propose a hidden Markov model that can integrate the stochastic process of mast flowering and the meteorological conditions influencing flower formation to predict the annual birch pollen concentration. In experiments conducted, the model was trained and validated by using data in Hokkaido, Japan covering 22 years. In the model, the hidden Markov sequence was assigned to represent the recurrence of mast years via a transition matrix, and the observation sequences were designated as meteorological conditions in the previous summer, which are governed by hidden states with emission distribution. The proposed model achieved accuracies of 83.3% in the training period and 75.0% in the test period. Thus, the proposed model can provide an alternative perspective toward the SPI forecast and probabilistic information of pollen levels as a useful reference for allergy stakeholders. Unlabelled Image • A hidden Markov model (HMM) is proposed to predict seasonal pollen index (SPI). • Mast flowering stochasticity is combined with flower formation influencing factors. • Mast years' recurrence is parameterized via a transition matrix. • Relation between meteorological factors and SPI defines via emission distribution. • Probability of the next pollen level becomes available by using stochastic model. [ABSTRACT FROM AUTHOR]

This study proposes the design of conductive bridge random access memory (CBRAM) using an indium electrode, which diffuses into hafnium oxide. The device is found to exhibit good operating characteristics, maintaining a large operation window, low set and reset voltages, and advantageous operation speed, thereby reducing operating power consumption. Electrical experiments, transmission electron microscopy, and energy‐dispersive spectroscopy confirm that the device exhibits the characteristics of a CBRAM device. In addition, due to the large operation window of this In electrode device, a combination of two of these CBRAM can act as a complementary resistive switching (CRS) device with a large memory window. [ABSTRACT FROM AUTHOR]

A rising forming voltage issue with scaling‐down resistive random access memory (RRAM) device cells is successfully solved by introducing new high‐permittivity (high‐k) material as the side‐wall spacer structure. As reported by Ting‐Chang Chang, Kuan‐Chang Chang, and co‐workers in article number 1700171, both COMSOL‐simulated electrical field and electrical measurements confirm the confined the electrical field by the surrounded high‐k spacer. The cross section views clearly show the different structures with a spacer. [ABSTRACT FROM AUTHOR]

Ta–N–Al thin films were produced by reactive sputtering with two different TaAl alloys (Al 10 at.% and 20 at.%) for use as resistive materials for thin film chip resistors. Changing the N 2 gas flow of the N 2 /Ar plasma and the Al ratio in TaAl alloy resulted in different microstructures and electrical properties of the Ta–N–Al thin film. The resistivity of the thin film sputtered by TaAl (Al 20 at.%) alloy was 1.23 times that sputtered by Ta under 20% N 2 /Ar. After deposition, rapid thermal processing was applied to anneal the thin films for 5 min at 600 °C, 650 °C, and 700 °C under N 2 (99.995%) atmosphere, causing the Ta 2 N and TaN crystalline phase formation. Al in Ta–N–Al was observed to hinder Ta 2 N and TaN crystalline phase formation during annealing. It is crucial to dope Al ith Ta–N appropriately to obtain a near-zero temperature coefficient of resistance (TCR) after annealing. The TCR of Ta–N–Al thin film, sputtered by TaAl (Al 20 at.%) alloy, was substantially affected by the annealing temperature. However, the thin film sputtered by TaAl (Al 10 at.%) alloy under 16% N 2 /Ar can achieve a TCR of −1.8 ppm/°C and 1.4 ppm/°C after annealing at 600 °C and 650 °C, respectively. • Ta-N-Al with adequate Al has a higher resistivity than Ta-N. • Get near-zero TCR of Ta-N-Al by annealing within a specific temperature range. • Al in Ta-N-Al hinders Ta 2 N and TaN grain growth during annealing. [ABSTRACT FROM AUTHOR]