Precharging method and programming method for selected and unselected sub-blocks of 3D memory strings in a device
Provided are a precharging method and a programming method for a 3D memory device that includes a top-deck word line group, a middle dummy word line group, a bottom-deck word line group, and a bottom dummy word line group. The precharging method includes: selecting a word line to be programmed; determining whether the word line is in the top- or bottom-deck word line group; applying a precharge on voltage to the middle dummy word line group to turn on a channel to precharge the channel when the word line is in the top-deck word line group; and applying a precharge off voltage to the middle dummy word line group to turn off the channel to not precharge the channel when the word line is in the bottom-deck word line group. This method is suitable for a 3D NAND flash memory having high capacity and high performance.
1 . A precharging method for a 3D memory device, which at least comprises a top-deck word line group, a middle dummy word line group, a bottom-deck word line group, and a bottom dummy word line group arranged in sequence, the precharging method comprising:
selecting a word line sequentially from the top-deck word line group and the bottom-deck word line group to be programmed;
determining whether the word line selected is in the top-deck word line group or the bottom-deck word line group;
applying a precharge on voltage to the middle dummy word line group so that a precharge voltage reaches a channel at a position corresponding to the middle dummy word line group in response to the word line being in the top-deck word line group; and
applying a precharge off voltage to the middle dummy word line group so that the precharge voltage does not reach the channel at the position corresponding to the middle dummy word line group in response to the word line being in the bottom-deck word line group,
wherein the precharge on voltage is much smaller than a voltage for programming the word line selected, and the precharge off voltage is OV.
2 . The precharging method for the 3D memory device according to claim 1 , wherein the 3D memory device further comprises a common source line, and the precharge voltage is applied from the common source line.
3 . The precharging method for the 3D memory device according to claim 1 , further comprising applying the precharge on voltage to the bottom dummy word line group when precharging.
4 . The precharging method for the 3D memory device according to claim 1 , wherein the 3D memory device comprises an array comprising a plurality of memory cells, and the plurality of memory cells are single-level cells, multiple-level cells, triple-level cells, or quad-level cells.
5 . The precharging method for the 3D memory device according to claim 1 , wherein the 3D memory device is a 3D NAND memory device.
6 . A precharging method for a 3D memory device, which at least comprises multiple decks of word line groups, a plurality of middle dummy word line groups, and a bottom dummy word line group, wherein the bottom dummy word line group is located below a lowermost deck of word line group of the multiple decks of word line groups, and each of the plurality of middle dummy word line groups is arranged between every two decks of word line groups of the multiple decks of word line groups, the precharging method comprising:
selecting a word line sequentially from the multiple decks of word line groups to be programmed;
determining in which one deck of word line group of the multiple decks of word line groups the word line is located in;
applying a precharge on voltage to each middle dummy word line group below the one deck of word line group so that a precharge voltage reaches a channel at a position corresponding to each middle dummy word line group below the one deck of word line group; and
applying a precharge off voltage to each middle dummy word line group above the one deck of word line group so that the precharge voltage does not reach the channel at the position corresponding to each middle dummy word line group above the one deck of word line group,
wherein the precharge on voltage is much smaller than a voltage for programming the word line selected, and the precharge off voltage is OV.
7 . The precharging method for the 3D memory device according to claim 6 , wherein the 3D memory device further comprises a common source line, and the precharge voltage is applied from the common source line.
8 . The precharging method for the 3D memory device according to claim 6 , further comprising applying the precharge on voltage to the bottom dummy word line group when precharging.
9 . The precharging method for the 3D memory device according to claim 6 , wherein the 3D memory device comprises an array comprising a plurality of memory cells, and the plurality of memory cells are single-level cells, multiple-level cells, triple-level cells, or quad-level cells.
10 . The precharging method for the 3D memory device according to claim 6 , wherein the 3D memory device is a 3D NAND memory device.
11 . A programming method for a 3D memory device, which at least comprises a top-deck word line group, a middle dummy word line group, a bottom-deck word line group, and a bottom dummy word line group arranged in sequence, the programming method comprising:
selecting a word line sequentially from the top-deck word line group and the bottom-deck word line group to be programmed;
determining whether the word line selected is in the top-deck word line group or the bottom-deck word line group;
applying a precharge on voltage to the middle dummy word line group so that a precharge voltage reaches a channel at a position corresponding to the middle dummy word line group in response to the word line being in the top-deck word line group;
applying a precharge off voltage to the middle dummy word line group so that the precharge voltage does not reach the channel at the position corresponding to the middle dummy word line group in response to the word line being in the bottom-deck word line group; and
applying a programming voltage to the word line selected after completing applying the precharge voltage,
wherein the precharge on voltage is much smaller than a voltage for programming the word line selected, and the precharge off voltage is OV.
12 . The programming method for the 3D memory device according to claim 11 , wherein the 3D memory device further comprises a common source line, and the precharge voltage is applied from the common source line.
13 . The programming method for the 3D memory device according to claim 11 , further comprising applying the precharge on voltage to the bottom dummy word line group when precharging.
14 . The programming method for the 3D memory device according to claim 11 , wherein the 3D memory device comprises an array comprising a plurality of memory cells, and the plurality of memory cells are single-level cells, multiple-level cells, triple-level cells, or quad-level cells.
15 . The programming method for the 3D memory device according to claim 11 , wherein the 3D memory device is a 3D NAND memory device.