Patent ID: 8503230
Filing Date: 2013-08-06
Classification: G11C

Abstract:
1. An access method of a non-volatile memory device comprising: detecting a threshold voltage variation of a first memory cell based on first data to be programmed in the first memory cell, the threshold voltage variation of the first memory cell being capable of physically affecting a second memory cell; assigning the second memory cell to a sub-distribution selected from among a plurality of sub-distributions according to a distance of the threshold voltage variation of the first memory cell, the plurality of sub-distributions corresponding to a target distribution of the second memory cell, at least one of the plurality of sub-distributions having a threshold voltage range that is not entirely within a threshold voltage range of the target distribution; programming the second memory cell; and programming the first data in the first memory cell; wherein a verification voltage for programming the second memory cell is selected to be identical to or lower than a verification voltage corresponding to the target distribution of the second memory cell, and wherein the programming of the second memory cell takes place after assigning the second memory cell to the selected sub-distribution and before programming the first data in the first memory cell.