【作者】 周文；

【导师】 乔东海；

【作者基本信息】 苏州大学 ， 集成电路工程（专业学位）， 2013， 硕士

【摘要】 闪存（Flash Memory）是一种长寿命的非易失性（在断电情况下仍能保持所存储的数据信息）的存储器。由于其断电后仍能保存数据，闪存通常被用来保存设置信息，如在电脑的BIOS（基本输入输出程序）、PDA（个人数字助理）、数码相机中保存资料等。闪存分为NOR型与NAND型，目前NAND闪存是一种比硬盘驱动器更好的存储方案，这在不超过8GB的低容量应用中表现的犹为明显。随着人们持续追求功耗更低、重量更轻和性能更佳的产品，NAND闪存正被证明极具吸引力。NAND闪存作为一种比较实用的固态硬盘存储介质，有自己的一些物理特性，NAND闪存的电荷非常不稳定，在写入（编程）时很容易对邻近的单元造成干扰，干扰后会让附近单元的电荷脱离实际的逻辑数值，造成位（bit）出错。由于阈值电压接近的关系，MLC相对SLC来说更容易受到干扰，如何改善写入（编程）干扰是本文研究的主要方向。写入（编程）干扰指的是，某个页(page)在写入（编程）时，邻近位（bit）的电压也被升高了，造成位（bit）出错。为了保证写入数据的完整性,研究如何减少写入（编程）干扰造成的数据出错显得尤为重要，除了芯片级测试参数的修改与写入（编程）的方法可以改善写入（编程）干扰，在系统级测试中，通过ECC算法也可以纠正这些位（bit）的错误。随着NAND闪存工艺的不断提升，同样大小的晶片上被封装入更多的单元，造成干扰越来越厉害，所以需要更强大的ECC来纠正位（bit）。本文重点研究了NAND闪存写入（编程）干扰的原理，由浅入深的介绍了NAND闪存写入（编程）干扰的特性与种类以及各自的改善方法，并结合NAND闪存实际测试过程中遇到的写入（编程）干扰问题，对NAND闪存写入（编程）干扰提出了合理的改善意见与建议。更多还原

【Abstract】 Flash memory is an electronic non-volatile computer storage medium that can beelectrically erased and reprogrammed, and get back stored information even after poweredoff. Flash memory developed from EEPROM (electrically erasable programmableread-only memory). There are two main types of flash memory, which are named after theNAND and NOR logic gates. NAND flash has reduced erase and write times, and requiresless chip area per cell, allowing greater storage density and lower cost per bit than NORflash, thus NAND flash is very suitable for use in mass-storage devices, such as memorycards.NAND flash devices have rapidly become the preferred choice for high-density，nonvolatile memory storage，particularly in mobile products. As higher-density NANDdevices become available，sometimes they are used to replace lower-density hard drives inmobile and embedded systems.This trend will likely continue as NAND device densitiesincrease and prices decrease[1].NAND device will face programming disturbance due to physical design.Programming disturbance—In this failure mode, refers to a bit is unintentionallyprogrammed from “1” to “0” during the programming of a page. The bit error may occureither on the page being programmed or on another page in the block. To recover fromprogramming disturbance errors, we have to develop right test method and parameterduring NAND flash testing, besides above corrective measure, the ECC also can be used torecover data from programming disturbance errors.This article mainly investigates on how to prevent programming disturbance duringtesting.更多还原