Boosting for non-volatile storage using channel isolation switching
First Claim
1. A method for operating non-volatile storage, comprising:
- performing first boosting of at least one NAND string on a source side of a first word line before boosting the at least one NAND string on a drain side of a second word line, the second word line is on a drain side of the first word line, a plurality of word lines including the first and second word lines are associated with the at least one NAND string, and the at least one NAND string has a plurality of non-volatile storage elements;
during the first boosting, applying a voltage to the first word line for providing a first non-volatile storage element of the plurality of non-volatile storage elements which is associated with the first word line in a conducting state, and applying a voltage to the second word line for providing a second non-volatile storage element of the plurality of non-volatile storage elements which is associated with the second word line in a conducting state; and
performing second boosting of the at least one NAND string on the drain side of the second word line, after the first boosting, while applying a voltage to the first word line for providing the first non-volatile storage element in a non-conducting state, and while applying a program voltage to the second word line.
3 Assignments
0 Petitions
Accused Products
Abstract
Program disturb is reduced in non-volatile storage by preventing source side boosting in selected NAND strings. A self-boosting mode which includes an isolation word line is used. A channel area of an inhibited NAND string is boosted on a source side of the isolation word line before the channel is boosted on a drain side of the isolation word line. Further, storage elements near the isolation word line are kept in a conducting state during the source side boosting so that the source side channel is connected to the drain side channel. In this way, in selected NAND strings, source side boosting can not occur and thus program disturb due to source side boosting can be prevented. After the source side boosting, the source side channel is isolated from the drain side channel, and drain side boosting is performed.
-
Citations
33 Claims
-
1. A method for operating non-volatile storage, comprising:
-
performing first boosting of at least one NAND string on a source side of a first word line before boosting the at least one NAND string on a drain side of a second word line, the second word line is on a drain side of the first word line, a plurality of word lines including the first and second word lines are associated with the at least one NAND string, and the at least one NAND string has a plurality of non-volatile storage elements; during the first boosting, applying a voltage to the first word line for providing a first non-volatile storage element of the plurality of non-volatile storage elements which is associated with the first word line in a conducting state, and applying a voltage to the second word line for providing a second non-volatile storage element of the plurality of non-volatile storage elements which is associated with the second word line in a conducting state; and performing second boosting of the at least one NAND string on the drain side of the second word line, after the first boosting, while applying a voltage to the first word line for providing the first non-volatile storage element in a non-conducting state, and while applying a program voltage to the second word line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A method for operating non-volatile storage, comprising:
-
performing first boosting of at least one NAND string on a side of a first non-volatile storage element in the at least one NAND string which is before the first non-volatile storage element in a programming sequence; during the first boosting, providing the first non-volatile storage element and a second non-volatile storage element in the at least one NAND string which is on a side of the first non-volatile storage element which is after the first non-volatile storage element in the programming sequence in a conducting state; and performing second boosting of the at least one NAND string, after the first boosting, on a side of the second non-volatile storage element which is after the second non-volatile storage element in the programming sequence while providing the first storage element in a non-conducting state. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
-
-
26. A method for operating non-volatile storage, comprising:
-
(a) in a first time period; (i) applying voltages to a first set of word lines on a source side of a particular word line in a set of word lines for boosting a first channel region of at least one NAND string; (ii) applying voltages to a second set of word lines which includes the particular word line, the second set of word lines is on a drain side of the first set of word lines, to provide non-volatile storage elements in the at least one NAND string which are associated with the second set of word lines in a conducting state; and (iii) applying voltages to a third set of word lines on a drain side of the second set of word lines, to avoiding boosting of a second channel region of the at least one NAND string; and (b) in a second time period which follows the first time period; (i) applying voltages to the third set of word lines for boosting the second channel region of the at least one NAND string; (ii) applying a program voltage to a word line in the second set of word lines; and (iii) applying a voltage to the particular word line to isolate the first channel region from the second channel region. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33)
-
Specification