Micron (Italy)

The determination of limit of quantification (LOQ) is one of the tasks specified in the validation process of a microbiological method. So far a detailed procedure for doing it is still lacking. Given the LOD (limit of detection), or data for estimating the LOD, we propose a procedure for determining the LOQ based on a Poisson confidence interval and a probability interval. This approach assures that data generated with mean at the LOQ will be higher than the LOD with high probability. We determine the required number of replicates in the validation test used to determine the LOD and the LOQ using the negative binomial probability density function that models over-dispersion of growth media plate count data in validation tests. The objective is to facilitate the determinations of some parameters commonly used in microbiological testing, such as setting control limits and suitable number of growth media plate counts. Key words: microbiological methods, limit of detection (LOD), limit of quantification (LOQ), confidence intervals.

The physics mechanism behind the polarity effect at the basis of the Single-chalcogenide Xpoint Memory (SXM) is investigated through dedicated experiments, DFT-based atomistic models and TCAD simulations. The resulting model takes into account the modification of the chalcogenide glass band structure attained upon quenching under high electric field and current. Once implemented inside a TCAD simulation tool, the model is capable of matching all of the relevant experimental trends of the SXM window vs active material thickness, temperature, and alloy stoichiometry. This is the first physically based model able to explain the basic functional characteristics of the SXM memory technology.

In this letter, through experimental evidence collected at room temperature and in the deep-cryogenic regime, we demonstrate that the so-called vertical charge loss from the gate stack of 3-D charge-trap NAND Flash memories is a process featuring widely distributed time constants. Results reveal that the turn-on of these time constants depends on the temperature at which the program operation is carried out. This, combined with the dependence of the time constants on the temperature at which vertical charge loss is monitored, gives rise to an apparent activation energy of the cell threshold-voltage transient during data retention that is close to zero when data retention and program occur at the same temperature. This phenomenology must be carefully taken into account when trying to extend the working temperature of NAND Flash memories down to the deep-cryogenic regime.

With the recent evolution of AI, our digital world, constructed by networks, is advancing rapidly and driving demand for data bandwidth and transfer speed everywhere from mobiles to data centers, regardless of form factor. This paper presents a 1Tb 3b/cell 3DNAND Flash on 2YY Tiers with a 6-plane and 3.6GT/s data-transfer features designed for a variety of applications that require high bandwidth.

In this paper, we report clear experimental evidence proving that programmed cells in a 3D NAND Flash memory array may experience an unexpected average increase in their threshold voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> ) during high-temperature data retention. The phenomenon is explored as a function of the V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> level of the monitored cells, the string back-pattern, and the data-retention temperature. A physical picture is then proposed to explain its origin, which is traced back to the depassivation of some traps in the polysilicon channel of the 3D NAND strings. Results point out a new reliability issue to address and tackle in the design of next generation 3D NAND Flash technologies.

The sensitivity of vertical-channel 3-D NAND Flash memories to wide-energy spectrum neutrons is investigated as a function of cell depth in the pillars. Errors are found to be less numerous at the center of the pillar, mainly due to the impact of top-to-bottom tapering on the electrical characteristics of the floating gate (FG) cells and, to a smaller extent, to a different generation of neutron secondaries as a function of depth.

Model order reduction (MOR) is usually equipped with two stages: the offline stage and the online stage.For many intrusive MOR methods that are based on projection, the offline stage is usually realized via a greedy algorithm.The greedy algorithm is used to properly select important parameter samples that contribute most to the solution space.The offline computational time is basically the runtime of the greedy algorithm.For large-scale systems, the offline computation is expensive and the runtime is longer than several hours even if it is run on a high-performance server.Sometimes, the system is not very large, for example, the number of degrees of freedom is only O(10 5 ), but the system structure is complicated such that the greedy algorithm still takes long time to converge.Once the reduced-order model is obtained, the online stage of querying the reduced-order model for simulation is very fast and in real-time.This work concerns a strategy of significantly accelerating the greedy algorithm.We propose multifidelity error estimators and replace the high-fidelity error estimator in the greedy algorithm.In fact, a bi-fidelity error estimation has been used in the adaptive greedy algorithm proposed in [1] without being formally defined.To further improve the convergence speed of the greedy algorithm, we propose multi-fidelity error estimation built upon the bi-fidelity error estimation.Here, we use a more efficient high-fidelity error estimator than the two different high-fidelity error estimators used in [1].Although the proposed multi-fidelity error estimation is dependent on the original high-fidelity error estimator, the concept of using multi-fidelity error estimation is generic and can be extended to develop multi-fidelity error estimation associated with other high-fidelity error estimators.The multi-fidelity error estimator is then used to adaptively update the training set of the greedy algorithm, keeping the offline computational costs on a possibly lowest level.Consequently, the computational complexity at each iteration of the greedy algorithm is reduced and the algorithm converges more than 3 times faster without incurring noticeable accuracy loss.

The Deformable Mirrors are, with the wavefront sensors, the core of the adaptive optics system of MORFEO (formerly known as MAORY), the first light AO system for ELT. Such large deformable mirrors (about convex 930 and concave 1220 mm) and the large number of modes (about 900 and 1000 modes) will allow a fitting error below 40 nm RMS on the atmospheric turbulence layers which they are conjugated to with a worst seeing case of 1.5 arcsec. In this paper we will briefly present the status of the design and the performances reached.

We studied the secondary byproducts created by high-energy protons inside a single-event upset (SEU) detector based on 3-D NAND Flash memories, extending the previously developed methodology used for detecting heavy ions. The radiation response of the SEU monitor was discussed as a function of proton energy, analyzing parameters such as the number of clusters per particle, the cluster size, and the angle of the generated secondaries. The results provide interesting insight into the nuclear reactions occurring in state-of-the-art electronic chips, in addition to showing the usefulness of 3-D NAND Flash memories for monitoring proton beams.