Anti-interference method for NANDFLASH programming

Abstract

The invention discloses an anti-interference method for NANDFLASH programming. The method comprises the following steps of: applying programming voltage to a selected word line, and applying break-over voltage to an unselected word line; carrying out a read operation on the selected word line, and determining whether the word line succeeds in being programmed or not; and if the state of the read operation is programming failure, increasing a current programming voltage value and a current break-over voltage value by a set stepping value, and returning to execute the read operate until the state of the read operation is programming success. By use of the anti-interference method, which is provided by the embodiment of the invention, for NANDFLASH programming, a proper voltage window between the programming voltage and the break-over voltage is guaranteed, and programming interference and break-over voltage interference are effectively lowered.

Description

technical field [0001] The embodiment of the present invention relates to the field of integrated circuits, in particular to an anti-interference method for NAND FLASH programming. Background technique [0002] NAND FLASH is a non-volatile flash memory that can provide high capacity within a given chip size. NANDFLASH uses pages as the basic unit for storage and block as the basic unit for erasing. It has a very fast writing and erasing speed and is a better storage device than hard drives. [0003] While having many advantages, NANDFLASH applies a programming voltage (VPP) to the selected word line during the programming process using the SBPI (Self-boosted programinhibit) programming scheme, and applies a turn-on voltage (VPASS) to the unselected word line. The selected word line adopts the ISPP programming sequence. When the programming voltage gradually increases to a higher voltage, if the conduction voltage remains at the initial voltage, then the high voltage applied...

AI Technical Summary

Problems solved by technology

The selected word line adopts the ISPP programming sequence. When the programming voltage gradually increases to a higher voltage, if the conduction voltage remains at the initial voltage, then the high voltage applied on the selected word line in the final stage will affect the adjacent unselected words. program disturb

On the other hand, if a higher conduction voltage is applied to the unselected word line from the beginning, the higher conduction voltage may cause conduction voltage interference to the data in the memory cell, forming a soft programming effect

[0004] It can be seen that during the programming process of NAND FLASH, if a higher programming voltage is applied to the selected word line, it will cause programming interference to its adjacent unselected word lines, and when the applied programming voltage is lower, it will cause conduction voltage interference.

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