Vertical 3d Memory Technologies

The large scale integration and planar scaling of individual system chips is reaching an expensive limit. If individual chips now, and later terrabyte memory blocks, memory macros, and processing cores, can be tightly linked in optimally designed and processed small footprint vertical stacks, then performance can be increased, power reduced and cost contained. This book reviews for the electronics industry engineer, professional and student the critical areas of development for 3D vertical memory chips including: gate-all-around and junction-less nanowire memories, stacked thin film and double gate memories, terrabit vertical channel and vertical gate stacked NAND flash, large scale stacking of Resistance RAM cross-point arrays, and 2.5D/3D stacking of memory and processor chips with through-silicon-via connections now and remote links later. Key features: Presents a review of the status and trends in 3-dimensional vertical memory chip technologies. Extensively reviews advanced vertical memory chip technology and development Explores technology process routes and 3D chip integration in a single reference

This book walks the reader through the next step in the evolution of NAND flash memory technology, namely the development of 3D flash memories, in which multiple layers of memory cells are grown within the same piece of silicon. It describes their working principles, device architectures, fabrication techniques and practical implementations, and highlights why 3D flash is a brand new technology. After reviewing market trends for both NAND and solid state drives (SSDs), the book digs into the details of the flash memory cell itself, covering both floating gate and emerging charge trap technologies. There is a plethora of different materials and vertical integration schemes out there. New memory cells, new materials, new architectures (3D Stacked, BiCS and P-BiCS, 3D FG, 3D VG, 3D advanced architectures); basically, each NAND manufacturer has its own solution. Chapter 3 to chapter 7 offer a broad overview of how 3D can materialize. The 3D wave is impacting emerging memories as well and chapter 8 covers 3D RRAM (resistive RAM) crosspoint arrays. Visualizing 3D structures can be a challenge for the human brain: this is way all these chapters contain a lot of bird’s-eye views and cross sections along the 3 axes. The second part of the book is devoted to other important aspects, such as advanced packaging technology (i.e. TSV in chapter 9) and error correction codes, which have been leveraged to improve flash reliability for decades. Chapter 10 describes the evolution from legacy BCH to the most recent LDPC codes, while chapter 11 deals with some of the most recent advancements in the ECC field. Last but not least, chapter 12 looks at 3D flash memories from a system perspective. Is 14nm the last step for planar cells? Can 100 layers be integrated within the same piece of silicon? Is 4 bit/cell possible with 3D? Will 3D be reliable enough for enterprise and datacenter applications? These are some of the questions that this book helps answering by providing insights into 3D flash memory design, process technology and applications.

Offers a comprehensive overview of NAND flash memories, with insights into NAND history, technology, challenges, evolutions, and perspectives Describes new program disturb issues, data retention, power consumption, and possible solutions for the challenges of 3D NAND flash memory Written by an authority in NAND flash memory technology, with over 25 years’ experience

Emerging Memories: Technologies and Trends attempts to provide background and a description of the basic technology, function and properties of emerging as well as discussing potentially suitable applications. This book explores a range of new memory products and technologies. The concept for some of these memories has been around for years. A few completely new. Some involve materials that have been in volume production in other type of devices for some time. Ferro-electrics, for example, have been used in capacitors for more than 30 years. In addition to looking at using known devices and materials in novel ways, there are new technologies being investigated such as DNA memories, light memories, molecular memories, and carbon nanotube memories, as well as the new polymer memories which hold the potential for the significant manufacturing reduction. Emerging Memories: Technologies and Trends is a useful reference for the professional engineer in the semiconductor industry.

Rising consumer demand for low power consumption electronics has generated a need for scalable and reliable memory devices with low power consumption. At present, scaling memory devices and lowering their power consumption is becoming more difficult due to unresolved challenges, such as short channel effect, Drain Induced Barrier Lowering (DIBL), and sub-surface punch-through effect, all of which cause high leakage currents. As a result, the introduction of different memory architectures or materials is crucial. Nanomaterials-based Charge Trapping Memory Devices provides a detailed explanation of memory device operation and an in-depth analysis of the requirements of future scalable and low powered memory devices in terms of new materials properties. The book presents techniques to fabricate nanomaterials with the desired properties. Finally, the book highlights the effect of incorporating such nanomaterials in memory devices. This book is an important reference for materials scientists and engineers, who are looking to develop low-powered solutions to meet the growing demand for consumer electronic products and devices. Explores in depth memory device operation, requirements and challenges Presents fabrication methods and characterization results of new nanomaterials using techniques, including laser ablation of nanoparticles, ALD growth of nano-islands, and agglomeration-based technique of nanoparticles Demonstrates how nanomaterials affect the performance of memory devices

This book offers a balanced and comprehensive guide to the core principles, fundamental properties, experimental approaches, and state-of-the-art applications of two major groups of emerging non-volatile memory technologies, i.e. spintronics-based devices as well as resistive switching devices, also known as Resistive Random Access Memory (RRAM). The first section presents different types of spintronic-based devices, i.e. magnetic tunnel junction (MTJ), domain wall, and skyrmion memory devices. This section describes how their developments have led to various promising applications, such as microwave oscillators, detectors, magnetic logic, and neuromorphic engineered systems. In the second half of the book, the underlying device physics supported by different experimental observations and modelling of RRAM devices are presented with memory array level implementation. An insight into RRAM desired properties as synaptic element in neuromorphic computing platforms from material and algorithms viewpoint is also discussed with specific example in automatic sound classification framework.