NAND flash memory technology utilizing fringing electric field

2012 ◽  
Vol 52 (4) ◽  
pp. 662-669 ◽  
Author(s):  
Jong-Ho Lee ◽  
Sang-Goo Jung
Keyword(s):  
Electric Field ◽  
Flash Memory ◽  
Nand Flash ◽  
Nand Flash Memory ◽  
Fringing Electric Field

scholarly journals A New Read Scheme for Alleviating Cell-to-Cell Interference in Scaled-Down 3D NAND Flash Memory

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1775
Author(s):  
Jae-Min Sim ◽  
Myounggon Kang ◽  
Yun-Heub Song
Keyword(s):  
Electric Field ◽  
Flash Memory ◽  
Computer Aided Design ◽  
Fundamental Problem ◽  
Adjacent Cell ◽  
Nand Flash ◽  
Nand Flash Memory ◽  
Fundamental Cause ◽  
Tcad Simulation ◽  
Aided Design

In this paper, we investigated the cell-to-cell interference in scaled-down 3D NAND flash memory by using a Technology Computer-Aided Design (TCAD) simulation. The fundamental cause of cell-to-cell interference is that the electric field crowding point is changed by the programmed adjacent cell so that the electric field is not sufficiently directed to the channel surface. Therefore, the channel concentration of the selected cell is changed, leading to a Vth shift. Furthermore, this phenomenon occurs more severely when the selected cell is in an erased state rather than in a programmed state. In addition, it was confirmed that the cell-to-cell interference by the programmed WLn+1 is more severe than that of WLn−1 due to the degradation of the effective mobility effect. To solve this fundamental problem, a new read scheme is proposed. Through TCAD simulation, the cell-to-cell interference was alleviated with a bias having a ΔV of 1.5 V from Vread through an optimization process to have appropriate bias conditions in three ways that are suitable for each pattern. As a result, this scheme narrowed the Vth shift of 67.5% for erased cells and narrowed the Vth shift of 70% for programmed cells. The proposed scheme is one way to solve the cell-to-cell interference that may occur as the cell-to-cell distance decreases for a high stacked 3D NAND structure.

Novel Three Dimensional (3D) NAND Flash Memory Array Having Tied Bit-line and Ground Select Transistor (TiGer)

2012 ◽  
Vol E95.C (5) ◽  
pp. 837-841 ◽  
Author(s):  
Se Hwan PARK ◽  
Yoon KIM ◽  
Wandong KIM ◽  
Joo Yun SEO ◽  
Hyungjin KIM ◽  
...  
Keyword(s):  
Flash Memory ◽  
Three Dimensional ◽  
Nand Flash ◽  
Nand Flash Memory ◽  
Memory Array

scholarly journals Artificial Neural Network Assisted Error Correction for MLC NAND Flash Memory

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 879
Author(s):  
Ruiquan He ◽  
Haihua Hu ◽  
Chunru Xiong ◽  
Guojun Han
Keyword(s):  
Neural Network ◽  
Error Correction ◽  
Error Detection ◽  
Flash Memory ◽  
Nand Flash ◽  
Data Reliability ◽  
Nand Flash Memory ◽  
Process Technology ◽  
Noise Mitigation ◽  
Memory Channel

The multilevel per cell technology and continued scaling down process technology significantly improves the storage density of NAND flash memory but also brings about a challenge in that data reliability degrades due to the serious noise. To ensure the data reliability, many noise mitigation technologies have been proposed. However, they only mitigate one of the noises of the NAND flash memory channel. In this paper, we consider all the main noises and present a novel neural network-assisted error correction (ANNAEC) scheme to increase the reliability of multi-level cell (MLC) NAND flash memory. To avoid using retention time as an input parameter of the neural network, we propose a relative log-likelihood ratio (LLR) to estimate the actual LLR. Then, we transform the bit detection into a clustering problem and propose to employ a neural network to learn the error characteristics of the NAND flash memory channel. Therefore, the trained neural network has optimized performances of bit error detection. Simulation results show that our proposed scheme can significantly improve the performance of the bit error detection and increase the endurance of NAND flash memory.

scholarly journals Investigation of Re-program Scheme in Charge Trap Based 3D NAND Flash Memory

2021 ◽  
pp. 1-1
Author(s):  
Ting Cheng ◽  
Jianquan Jia ◽  
Lei Jin ◽  
Xinlei Jia ◽  
Shiyu Xia ◽  
...  
Keyword(s):  
Flash Memory ◽  
Program Scheme ◽  
Nand Flash ◽  
Nand Flash Memory ◽  
Charge Trap
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