公开(公告)号：US20210257035A1

公开(公告)日：2021-08-19

申请号：US16791253

申请日：2020-02-14

Applicant: Sandisk Technologies LLC

Inventor： Jayavel Pachamuthu ,  Dengtao Zhao

IPC: G11C16/34 ,  G11C16/08 ,  G11C16/28 ,  G11C16/12 ,  H01L21/762

Abstract: Techniques for reducing program disturb of memory cells which are formed in a NAND string extending in a lower tier and an upper tier of a stack, the lower tier comprising a first plurality of memory cells and the upper tier comprising a second plurality of memory cells, wherein each memory cell of the first and second pluralities of memory cells is connected to a respective word line. The NAND string includes a joint region formed of a dielectric material and disposed between the lower tier and the upper tier of the stack; a first non-data memory cell adjacent to and below the joint region; a second non-data memory cell adjacent to and above the joint region; and a conductive gate connected to the first non-data memory cell and the second non-data memory cell.

公开(公告)号：US10541037B2

公开(公告)日：2020-01-21

申请号：US16002793

申请日：2018-06-07

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Dengtao Zhao ,  Deepanshu Dutta

IPC: G11C16/34 ,  G11C8/08 ,  G11C16/04 ,  G11C7/04 ,  G11C16/12

Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.

公开(公告)号：US20190392894A1

公开(公告)日：2019-12-26

申请号：US16019141

申请日：2018-06-26

Applicant: SanDisk Technologies LLC

Inventor： Dengtao Zhao ,  Deepanshu Dutta ,  Zhenming Zhou

IPC: G11C11/56 ,  G11C16/26 ,  G11C16/24 ,  G11C16/34 ,  H01L27/11556 ,  G11C16/04 ,  G11C16/30 ,  H01L27/11582

Abstract: A memory system includes a sense system configured to control parasitic noise sources by increasing selected bit line or channel voltages during sense stages. The increase may be tied to a triggering threshold voltage level. That is, while performing a memory operation, the sense system may increase the selected bit line voltage level dependent on a reference voltage level or memory state associated with a sense stage being above the triggering threshold level.

公开(公告)号：US20190392893A1

公开(公告)日：2019-12-26

申请号：US16019456

申请日：2018-06-26

Applicant: SanDisk Technologies LLC

Inventor： Xiang Yang ,  Dengtao Zhao ,  Huai-Yuan Tseng ,  Deepanshu Dutta ,  Zhongguang Xu ,  Yanli Zhang ,  Jin Liu

IPC: G11C11/56 ,  G11C16/24 ,  G11C16/08 ,  G11C16/14 ,  G11C16/34 ,  G11C16/04

Abstract: Non-volatile memory strings may include multiple selection devices for coupling memory cell devices to a bit line. Different programming operations may be used to program various individual selection devices in a non-volatile memory cells string. For example, a control circuit may set a threshold voltage of a particular selection device to a value greater than a threshold voltage of another selection device. In another example, the control circuit may program the selection device using an initial sense time. Subsequent to programming the selection device using the initial sense time, the control circuit may program the selection device using a different sense time that is shorter than the initial sense time.

公开(公告)号：US20190378581A1

公开(公告)日：2019-12-12

申请号：US16002836

申请日：2018-06-07

Applicant: SANDISK TECHNOLOGIES LLC

Inventor： Dengtao Zhao ,  Peng Zhang ,  Nan Lu ,  Deepanshu Dutta

IPC: G11C16/34 ,  G11C16/10 ,  G11C16/08 ,  G11C16/04 ,  H01L27/11582 ,  H01L27/1157

Abstract: Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.

公开(公告)号：US10381083B1

公开(公告)日：2019-08-13

申请号：US16018018

申请日：2018-06-25

Applicant: SanDisk Technologies LLC

Inventor： Xiang Yang ,  Kun-Huan Shih ,  Matthias Baenninger ,  Huai-Yuan Tseng ,  Dengtao Zhao ,  Deepanshu Dutta

IPC: G11C11/34 ,  G11C16/14 ,  G11C16/24 ,  G11C16/30 ,  G11C16/08 ,  G11C16/34 ,  H01L27/1157 ,  G11C16/04 ,  H01L27/11524

Abstract: A memory device and associated techniques avoid a disturb of a select gate transistor during an erase operation for memory cells in a string. During the erase operation, a channel potential gradient near the select gate transistors is reduced when the voltages of the bit line and the substrate are suitably controlled. In one approach, the voltage of the substrate at a source end of the memory string is increased to an intermediate level first before being increased to the erase voltage threshold level while the voltage of the bit line is held at a reference voltage level to delay floating the voltage of the bit line. Another approach builds off the first approach by temporarily decreasing the voltage of the bit line to a negative level before letting the voltage of the bit line to float at the same time as the voltage of the substrate is increased to the erase voltage threshold level.

公开(公告)号：US12112812B2

公开(公告)日：2024-10-08

申请号：US17884929

申请日：2022-08-10

Applicant: SanDisk Technologies LLC

Inventor： Jiacen Guo ,  Dengtao Zhao ,  Xiang Yang

IPC: G11C16/04 ,  G11C16/10 ,  G11C16/34

CPC classification number: G11C16/3427 ,  G11C16/0483 ,  G11C16/10

Abstract: Non-volatile memory cells are programmed by pre-charging channels of unselected non-volatile memory cells connected to a selected data word line, boosting the channels of unselected non-volatile memory cells connected to the selected data word line after the pre-charging and applying a program voltage pulse to selected non-volatile memory cells connected to the selected data word line while boosting. The pre-charging includes applying pre-charge voltages to one set of data word lines and dummy word line(s) as well as applying overdrive voltages to another set of data word lines connected to already programmed memory cells. At the end of the pre-charging, the dummy word lines are ramped down to a resting voltage prior to lowering the data word lines to one or more resting voltages.

公开(公告)号：US11961573B2

公开(公告)日：2024-04-16

申请号：US17533292

申请日：2021-11-23

Applicant: SanDisk Technologies LLC

Inventor： Abhijith Prakash ,  Xiang Yang ,  Dengtao Zhao

IPC: G11C16/06 ,  G11C16/04 ,  G11C16/10 ,  G11C16/26 ,  G11C16/34

CPC classification number: G11C16/3459 ,  G11C16/0483 ,  G11C16/10 ,  G11C16/26

Abstract: A plurality of memory programming the memory cells to at least one programmed data state in a plurality of program-verify iterations. In each iteration, after a programming pulse, a sensing operation is conducted to compare the threshold voltages of the memory cells to a low verify voltage associated with a first programmed data state and to a high very voltage associated with the first programmed data state. The sensing operation includes discharging a sense node through a bit line coupled to one of the memory cells and monitoring a discharge time of the sense node. At least one aspect of the sensing operation is temperature dependent so that a voltage gap between the high and low verify voltages is generally constant across a range of temperatures.

公开(公告)号：US20240071529A1

公开(公告)日：2024-02-29

申请号：US17898850

申请日：2022-08-30

Applicant: SanDisk Technologies LLC

Inventor： Jiacen Guo ,  Dengtao Zhao ,  Xiang Yang

IPC: G11C16/34 ,  G11C16/04 ,  G11C16/08 ,  G11C16/10

CPC classification number: G11C16/3459 ,  G11C16/0433 ,  G11C16/08 ,  G11C16/102

Abstract: Memory cells are arranged as NAND strings to form a block divided into sub-blocks, and each NAND string includes a dummy memory cell connected to a dummy word line. Memory cells are programmed by applying programming pulses to a selected word line in a selected sub-block with program-verify performed between pulses. Unselected NAND strings are inhibited from programming by boosting channels of the unselected NAND strings in the selected sub-block from a positive pre-charge voltage to a boosted voltage. The pre-charging of the channels of unselected NAND strings is performed while lowering voltages at the end of program-verify by applying overdrive voltages to data word lines in a sub-block closer to the source line than the selected sub-block and lowering to a resting voltage a dummy word line between the sub-blocks prior to lowering to a resting voltage the data word lines in the sub-block closer to the source line.

公开(公告)号：US20230162809A1

公开(公告)日：2023-05-25

申请号：US17533292

申请日：2021-11-23

Applicant: SanDisk Technologies LLC

Inventor： Abhijith Prakash ,  Xiang Yang ,  Dengtao Zhao

IPC: G11C16/34 ,  G11C16/04 ,  G11C16/10 ,  G11C16/26

CPC classification number: G11C16/3459 ,  G11C16/0483 ,  G11C16/10 ,  G11C16/26

Abstract: A plurality of memory programming the memory cells to at least one programmed data state in a plurality of program-verify iterations. In each iteration, after a programming pulse, a sensing operation is conducted to compare the threshold voltages of the memory cells to a low verify voltage associated with a first programmed data state and to a high very voltage associated with the first programmed data state. The sensing operation includes discharging a sense node through a bit line coupled to one of the memory cells and monitoring a discharge time of the sense node. At least one aspect of the sensing operation is temperature dependent so that a voltage gap between the high and low verify voltages is generally constant across a range of temperatures.