A new ruler on the storage market: 3D-NAND flash for high-density memory and its technology evolutions and challenges on the future

Lee, Jae-Duk; Jang, Jae Hoon; Lim, Ji Hyoun; Shin, Youngsoo; Kyupil, Lee; Jung, Eun-Sung

doi:10.1109/iedm.2016.7838394

Cited by 41 publications

(18 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The revolutionary move to 3D memories was not without problems, as discussed in [29]. In fact, while traditional device reliability issues must still be accounted for, new phenomena came to prominence, which are not merely an extension of what has already been observed on planar devices, but rather a consequence of the different device and array fabrication.…”

Section: Introductionmentioning

confidence: 97%

Reliability of NAND Flash Memories: Planar Cells and Emerging Issues in 3D Devices

2017

View full text Add to dashboard Cite

Abstract:We review the state-of-the-art in the understanding of planar NAND Flash memory reliability and discuss how the recent move to three-dimensional (3D) devices has affected this field. Particular emphasis is placed on mechanisms developing along the lifetime of the memory array, as opposed to time-zero or technological issues, and the viewpoint is focused on the understanding of the root causes. The impressive amount of published work demonstrates that Flash reliability is a complex yet well-understood field, where nonetheless tighter and tighter constraints are set by device scaling. Three-dimensional NAND have offset the traditional scaling scenario, leading to an improvement in performance and reliability while raising new issues to be dealt with, determined by the newer and more complex cell and array architectures as well as operation modes. A thorough understanding of the complex phenomena involved in the operation and reliability of NAND cells remains vital for the development of future technology nodes.

show abstract

Section: Introductionmentioning

confidence: 97%

Reliability of NAND Flash Memories: Planar Cells and Emerging Issues in 3D Devices

2017

View full text Add to dashboard Cite

show abstract

“…In the area scaling technology, three dimensional (3D)-NAND flash memory has replaced conventional planar NAND devices owing to smaller size of NAND flash memory devices [1]. A high aspect ratio etching process and multiple dielectric deposition for charge trapping and isolation are required to perform area scaling in 3D-NAND flash memory; this increases the complexity of device manufacturing.…”

Section: Introductionmentioning

confidence: 99%

Deep Neural Network Modeling of Multiple Oxide/Nitride Deposited Dielectric Films for 3D-NAND Flash

Choi

Ho²,

Lee

et al. 2020

Appl. Sci. Converg. Technol.

View full text Add to dashboard Cite

The fast and accurate measurement of the thickness of multiple oxide/nitride layer deposition (MOLD) films is desirable to improve the quality of the plasma deposition process and potentially simplify the metrology in 3D NAND flash memory devices. In this study, we performed deep neural network modeling of the reflectance spectrum data of two pairs of oxide/nitride films on a silicon substrate. We designed a deep neural network model to estimate the thickness of four stacked thin-film layers and the MOLD film. Principle component analysis of this model was performed to develop another model with 27 features. Finally, a combined model was designed by fine tuning both the models and applying an ensemble algorithm to both. The mean absolute error of the combined predictive model was lower than that of the individual models. We verified the performance of the proposed model by considering the thin-film deposition mechanism with respect to the infrared reflectance metrology of MOLD thin films. This study demonstrates the potential of machine learning for predicting the thickness of multiple layered films, addressing the limitations of optical metrology.

show abstract

“…Three dimensional (3D) NAND architecture has become mainstream in NAND flash memory markets, producing better reliability, bit-density, and cost effectiveness than comparable technologies [1]- [3]. Manufacturers are massproducing 3D NAND flash memories through bit-cost scalable (BiCS) and terabit cell array transistor (TCAT) technologies [2], [3].…”

Section: Introductionmentioning

confidence: 99%

“…In this respect, 3D NAND technologies utilizing vertically stacked memory cells, to increase bit density, were more vulnerable to stress issues [5]- [7]. Specifically, the increased metal gate volume greatly influences the residual stress in the device by contributing to wafer bending, which therefore degrades the uniform depth of focus (DOF) required in the lithography process [1], [6], [7]. In additions, residual stress also enhances the non-uniformity in physical parameters, which is one of the causes of deterioration of device performance and reliability [4], [8].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Tungsten Volume on Residual Stress and Cell Characteristics in MONOS

Sim

Kino

et al. 2019

IEEE J. Electron Devices Soc.

View full text Add to dashboard Cite

The effect of residual stress during the tungsten deposition process were investigated using metal-oxide-nitride-oxide-semiconductor (MONOS) devices. The variation of residual stress due to tungsten volume was measured under tensile and compressive stress conditions. Residual stress increased in proportion to the deposition volume. Stress influenced the Si/SiO 2 interface and caused deterioration of the electrical properties, which was experimentally observed during measurements of the interface trap densities and memory windows. We confirmed that residual stress led to degradation of the cell characteristics of MONOS devices, and the absolute value of stress significantly affected these issues regardless of the polarity. From our experiments results, we can predict the degradation of cell characteristics in memory devices, and confirm the need for appropriate stress control in manufacturing process.INDEX TERMS Residual stress, tungsten volume, curvature method, interface trap densities, MONOS structure.

show abstract

A new ruler on the storage market: 3D-NAND flash for high-density memory and its technology evolutions and challenges on the future

Cited by 41 publications

References 3 publications

Reliability of NAND Flash Memories: Planar Cells and Emerging Issues in 3D Devices

Reliability of NAND Flash Memories: Planar Cells and Emerging Issues in 3D Devices

Deep Neural Network Modeling of Multiple Oxide/Nitride Deposited Dielectric Films for 3D-NAND Flash

The Effect of Tungsten Volume on Residual Stress and Cell Characteristics in MONOS

Contact Info

Product

Resources

About