A 512Gb 3b/Cell 3D flash memory on a 96-word-line-layer technology

Maejima, H.; Kanda, K.; Fujimura, Shigefumi; Takagiwa, Teruo; Ozawa, Susumu; Sato, Jumpei; Shindo, Yoshitaro; Sato, Manabu; Kanagawa, Naoaki; Musha, Junji; Inoue, Satoshi; Sakurai, Kazuo; Morozumi, N.; Fukuda, R.; Yuui, Shimizu; Hashimoto, Takahiro; Li, Xu; Shimizu, Yasuhiko; Abe, Kenichi; Yasufuku, Tadashi; Minamoto, Takatoshi; Yoshihara, H.; Yamashita, Takahiro; Satou, K.; Sugimoto, Tsuneaki; Fumihiro, Kono; Abe, Mitsuhiro; Hashiguchi, Tomoharu; Kojima, Masayasu; Suematsu, Yasuhiro; Shimizu, Toshihisa; Imamoto, Akihiro; Kobayashi, Naoki; Miakashi, M.; Yamaguchi, K.; Bushnaq, Sanad; Haibi, Hicham; Ogawa, M.; Ochi, Yusuke; Kubota, Kenro; Wakui, T.; He, Dong; Wang, Weihan; Minagawa, Hiroe; Nishiuchi, Tomoko; Nguyen, Hao; Kim, Kwang‐Ho; Cheah, Ken; Koh, Yee Lih; Lu, F.; Ramachandra, Venky; Rajendra, Srinivas; Choi, Steve K.; Payak, Keyur; Raghunathan, Namas; Georgakis, Spiros; Sugawara, Hiroshi; Lee, Seungpil; Futatsuyama, T.; Hosono, Koji; Shibata, Noboru; Hisada, T.; Kaneko, Tetsuya; Nakamura, Hiroshi

doi:10.1109/isscc.2018.8310321

Cited by 54 publications

(23 citation statements)

References 3 publications

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“…3(a)) between L A and B; C can be implemented as lookup tables stored in ROM. An optimal read voltage of the lower states calibrating read can be calculated using the high-state threshold voltage tracking read result [4]. In order to establish the mathematical model to calculate the threshold voltage shift of lower states, MLC 3D NAND Flash Memory has been tested to find the functional relationships between threshold voltage shift of P highest and threshold voltage shift of lower state.…”

Section: Numerical Solution Methods Of Mathematical Modelmentioning

confidence: 99%

“…2 can help us understand this method. Second, the threshold voltage shift of lower programmed threshold voltage distribution state can be calculated by determined functional relationships between threshold voltage shift of the highest programmed threshold voltage distribution state and threshold voltage shift of lower programmed threshold voltage distribution state [4]. Finally, read voltages used by read retry operations can be calculated by initial read voltage minus threshold voltage shift.…”

Section: Details Of Novel Valley Search Algorithmmentioning

confidence: 99%

“…With the development of multi-layer stack and multi-bit per cell storage technology, the storage density of 3D NAND Flash Memory has been increasing continuously in recent years. Toshiba has developed their 3b/Cell 3D Flash Memory on a 96-Word-Line-Layer technology in 2018 [4]. However, due to the increase of storage density, especially the development of multi-bit per cell storage technology, 3D NAND Flash Memory is more vulnerable to retention noise [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…However, due to the increase of storage density, especially the development of multi-bit per cell storage technology, 3D NAND Flash Memory is more vulnerable to retention noise [5,6]. Read retry using valley search algorithm which is also called threshold voltage tracking read [1,4] is one of the most effective methods to solve the problem of retention noise. The most simple and effective method of valley search is to increase or decrease read voltage at a certain interval until the optimal value of read voltage found [7].…”

Section: Introductionmentioning

confidence: 99%

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A fast read retry method for 3D NAND flash memories using novel valley search algorithm

Wang

et al. 2018

IEICE Electron. Express

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Read retry is one of the most effective methods to reduce retention errors caused by charge loss. A novel valley search algorithm for fast read retry method is proposed in this paper, which can reduce read operations to two times from at least three by conventional valley search algorithm [1, 8]. Experimental results illustrate that raw bit error rate (RBER) after read retry is reduced to 0.0344% using the novel valley search algorithm, which is within 4.41% of BCH(9088,8192,64) error correcting code (ECC) [2, 3] error correction capability.

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Section: Numerical Solution Methods Of Mathematical Modelmentioning

confidence: 99%

Section: Details Of Novel Valley Search Algorithmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A fast read retry method for 3D NAND flash memories using novel valley search algorithm

Wang

et al. 2018

IEICE Electron. Express

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“…This is because it overcomes many challenges faced by conventional planar (2-D) NAND flash memory [6,7] and meets the requirements for mass storage devices [8]. At present, 48, 64, and even 96-stacked layer 3-D TLC NAND flash memories are produced [8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Modeling of program Vth distribution for 3-D TLC NAND flash memory

Wang

Lun

et al. 2019

Sci. China Inf. Sci.

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This paper proposes a simulation method to model the program Vth distribution of 3-D vertical channel TLC/QLC charge-trapping NAND flash memory. The program Vth distribution can be calculated by considering ISPP noise, WL-WL interference, and the RTN effect of tunneling oxide and poly Si, which are the major physical factors affecting the width of program Vth distribution. Then, the program Vth distribution shapes with different ISPP incremental voltage steps are compared, and the results are found to be consistent with the experimental results. Code and layer-dependent coupling coefficients of WL-WL interference in 3-D vertical channel NAND flash memory are considered. The effect of RTN on the program Vth distribution is comprehensively studied. The program Vth distribution of a WL is calibrated with the measurement, and a good agreement is obtained, validating the array program Vth distribution simulation method. The simulation method can help in improving the reliability of 3-D TLC NAND flash memory and provides guidance for the design and optimization of 3-D QLC NAND flash memory technology.

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