Reserch Of NAND Programming Disturbance

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.