PREVENTION OF LATENT BLOCK FAILS IN THREE-DIMENSIONAL NAND

Technology is disclosed for detecting latent defects in non-volatile storage systems. Prior to writing data, a stress voltage is applied to SGS transistors in a 3D memory structure. After applying the stress voltage, the Vt of the SGS transistors are tested to determine whether they meet a criterion...

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Bibliographic Details
Main Authors Pachamuthu, Jayavel, Bhatt, Siddharth
Format Patent
LanguageEnglish
Published 29.09.2022
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Summary:Technology is disclosed for detecting latent defects in non-volatile storage systems. Prior to writing data, a stress voltage is applied to SGS transistors in a 3D memory structure. After applying the stress voltage, the Vt of the SGS transistors are tested to determine whether they meet a criterion. The criterion may be whether a Vt distribution of the SGS transistors falls within an allowed range. If the criterion is not met, then a sub-block mode may be enabled. In the sub-block mode, data is not written to memory cells in a sub-block that contains SGS transistors whose Vt does not meet the criterion. Hence, the possibility of data loss due to defective SGS transistors is avoided. However, in the sub-block mode, data is written to memory cells in a sub-block that does not contain SGS transistors whose Vt does not meet the criterion. Hence, data capacity is preserved.
Bibliography:Application Number: US202117213349