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The dual-deck architecture with aligned upper and lower decks is considered a promising technology to meet the demand of increasing word-line (WL) layers of 3D NAND flash. However, the relevant reliability studies are still lacking for the dual-deck 3D NAND array. In this work, it is reported an abnormal program disturbance phenomena of the bottom WLs in the upper-deck, and the physical mechanisms were studied. According to experimental analysis and TCAD simulations, the un-programmed dummy WLs at the joint region can introduce excessive joint residual electrons in the channel before the program, resulting in insufficient channel self-boosting potential, which is responsible for the degraded program disturbance. Thus, a novel program scheme is proposed to alleviate the program disturbance, which has been validated by experiments. [ABSTRACT FROM AUTHOR]

The detection of temporal correlations among event-driven data streams is widely demanded in data-intensive applications such as edge computing. In this work, temporal correlation detection is enabled by the combination of 3D NAND flash and in-memory computing. Different from mathematical scheme by covariance matrix calculation, here the detection is implemented by exploiting the physical process of charge tunneling and accumulation. Thus the intrinsic charge-trapping dynamics in 3D NAND flash can be leveraged to perform in-memory computing. The computing results are stored and imprinted in the threshold voltages of the 3D NAND device array, enabling co-existence of computation and storage in the same devices. On this basis, the validation of temporal correlation detection further paves the way for 3D NAND application in high-level non-von Neumann computing. [ABSTRACT FROM AUTHOR]

A novel axial strain sensor based on an optical microfiber coupler (OMC) operating at the dispersion turning point (DTP) was designed to realize high-sensitivity measurements of axial strain. First, we explain the measurement principle of axial strain sensors based on microfiber couplers. Then, we calculate the measurements, with the theoretical calculations showing that the sensor has high sensitivity when the effective refractive index (ERI) difference between the odd and even modes in the coupling region of the OMC is equal to zero. Finally, we carried out axial tensile experiments on the OMC. The results show that the OMC has the highest axial strain sensitivity when it operates at the DTP. The maximum sensitivity is 166.9 pm/ $\mu \varepsilon $ , with a linear range of 0- $400 ~\mu \varepsilon $. The sensor is highly sensitive to axial strains and has a simple structure. It has broad application prospects in the measurement of mechanical quantities such as strain, acceleration and vibration. [ABSTRACT FROM AUTHOR]