Inside_NAND_Flash_Memories.pdf

Inside_NAND_Flash_Memories.pdfRino micheloni· Luca Crippa· Alessia marelliInside nand flashMemoriesSpringerRino micheloniLuca CrippaIntegrated Device TechnologyForward InsightsAgrate BrianzaNorth yorkItalCanadarino. micheloni@ieee. orgluca.crippa @ieee.orgAlessia marelliIntegrated Device Technologyagrate brianzaItalylessiamarelli@gmail.comISBN97890-481-9430-8e-ISBN97890-481-9431-5DOI10.1007/978-90-481-9431-5Springer Dordrecht Heidelberg London New YorkLibrary of Congress Control Number: 2010931597O Springer Science+Business Media B.V. 2010No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or byany means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without writtenbeing entered and executed on a computer system, for exclusive use by the purchaser of the wor Ose ofpermission from the Publisher, with the exception of any material supplied specifically for the purpoCover design: eStudio Calamar SLPrinted on acid-free paperSpringerispartofSpringerScience+businessMedia(www.springer.com)PrefaceIn the last decade Flash cards became the most important digital storage supportIt is difficult to identify a single killer application(digital photography, MP3digital video, ...)or whether the success of this media support is due to itsusability in different applications. It is also difficult to state whether the recentlution in the infotainment area has been triggered by the availability of high-performance NAND Flash memories or if the extraordinary success of Flash cardsis a consequence of the establishment of new applicationsIn any case, independently of the cause-effect relationship linking new digitalapplications and Flash cards, to realize how NANd Flash memories entered in ourdaily life, it is sufficient to imagine as they would change our recent habits if theNAND memories disappeared suddenly. To take a picture it would be necessary tofind a film (as well as a traditional camera .), disks or even magnetic tapes wouldbe used to record a video or to listen a song, and a cellular phone would return tobe a simple mean of communication rather than a console for an extendedentertainmentThe development of nand Flash memories will not be set down on the mereevolution of these digital systems since a new killer application can trigger a furthersuccess for this memory support: the replacement of Hard Disk Drives(HDD)with Solid State Drives (SSD)The advantages of Ssd with respect to HDD are countless(higher read/writspeed, higher mechanical reliability, random access, silent operation, lower powerconsumption, lower weight, .. ) Nevertheless, the cost per gigabyte is stillsignificantly favorable to hDd and the success of ssd will depend only on theperformances that they will succeed in reachingThe present book, the fourth authored by rino micheloni and coworkers afterVLSI-Design of Non-volatiles Memories, Memories in Wireless Systems and ErrorCorrection Codes for Non-volatile Memories, all published by Springer, tacklesall the main aspects related to NANd Flash memories, from the physicaltechnological, and circuit issues to their use in Flash cards and SsdsAfter an extended market overview(Chap. 1), Chap 2 has been conceived as aguide for the entire book, so that the reader can directly reach the heart of theproblems that interest himThe following chapters deepen physical and technological aspects. In particularChaps. 3 and 4 tackle technological and reliability issues of traditional FloatingGate NAND memories, respectively, while the state-of-the-art of charge trappingtechnologies is effectively summarized in Chap 5Ⅴ i PrefaceThe central part of the book is dedicated to circuit issues: logic( Chap. 6),sensing circuits(Chaps. 8 and 9)and high voltage blocks( Chaps. 1l and 12)Other basic topics related to circuit aspects are also analyzed, such as theimplementation of Double Data Rate interfaces( Chap. 7), while multilevel storage(2 bits per cell) is presented in Chap. 10Techniques adopted to increase memory reliability and yield are discussedin Chaps. 13 and 14, the former dealing with redundancy, the latter with ErrorCorrection Codes. The test flux used by nand memories manufactures is describedin Chap 15Chapter 16 focus on nand devices storing 3 and 4 bits per cell that allowreaching the lower cost per gigabyte and that will conquer, in the next few years,the market of consumer applicationsThe last chapters are dedicated to the two most popular systems based onNAND memories: Flash cards( Chap. 17)and SsD(Chap. 18). The relationshipbetween Nand memories and system performances are highlightedFinally, Chap. 19 describes the effects of ionizing radiations on non-volatilememories, to understand whether NaNd memories can be safely used in spaceand military applicationsProf. Piero olivoDean of the Engineering FacultyUniversity of ferrara, ItalyAcknowledgementsAfter completing a project like a technical book, it is very hard to acknowledgeall the people who have contributed directly or indirectly with their work anddedicationFirst of all, we wish to thank all the authors of the contributed chaptersWe have to thank mark de Jongh for giving us the possibility of publishing thiswork and cindy zitter for her continuous supportLast but not least, we keep in mind all our present and past colleagues for theirsuggestions and fruitful discussionsRino. Luca and alessiaTable of contentsPrefaceAcknowledgementsvIII Market and applications for nand Flash memoriesGregory Wong2 NAND overview: from memory to systemsR. Micheloni, A Marelli and S. Commodaro3 Program and erase of Nand memory arrays55Cristoph Friederich4 Reliability issues of NAND Flash memoriesC. Zambelli. a. Chimenton and p. olivo5 Charge trap nand technologies115Alessandro grossi6 Control logic131A Marelli.R Micheloni andR. ravasio7 NAND DDR interface161Andrea silvagni8 Sensing circuits197L. Crippa and R. micheloni9 Parasitic effects and verify circuits235L. Crippa and R. michelonO MLC Storage261L Crippa and R Micheloni11 Charge pumps, voltage regulators and HV switchesR Micheloni and L Crippa