Apparatuses and methods for reducing read disturb
View Patent ↗Apparatuses and methods for reducing read disturb are described herein. An example apparatus may include a first memory subblock including a first select gate drain (SGD) switch and a first select gate source (SGS) switch, a second memory subblock including a second SGD switch and a second SGS switch, and an access line associated with the first and second memory subblocks. The apparatus may include a control unit configured to enable the first and second SGD switches and the first and second SGS switches during a first portion of a read operation and to provide a first voltage on the access line during the first portion. The control unit may be configured to disable the first SGD switch and the first SGS switches during a second portion of the read operation and to provide a second voltage on the access line during the second portion.
1. An apparatus, comprising:
a control unit coupled to a first select gate drain switch of a first memory subblock and a second select gate drain switch of a second memory subblock and a first select gate source switch of the first memory subblock and a second select gate source switch of the second memory subblock, the control unit configured to enable the first and second select gate drain switches and the first and second select gate source switches during a first portion of a read operation and to provide a first voltage on an access line coupled to memory cells of the first and second memory subblocks during the first portion of the read operation, the control unit further configured to disable the first select gate drain switch and the first select gate source switch during a second portion of the read operation and to provide a second voltage on the access line during the second portion of the read operation.
2. The apparatus of claim 1 , wherein the control unit is configured to enable one or more of the first and second select gate drain switches and the first and second select gate source switches by providing an active control signal.
3. The apparatus of claim 1 , wherein the control unit is configured to disable one or more of the first and second select gate drain switches and the first and second select gate source switches by providing an inactive control signal.
4. The apparatus of claim 1 , wherein the second voltage is greater than the first voltage.
5. The apparatus of claim 1 , wherein the control unit is configured to charge the access line to the first voltage during the first portion of the read operation.
6. The apparatus of claim 1 , wherein the control unit is configured to charge the access line to the second voltage during the second portion of the read operation.
7. The apparatus of claim 1 , wherein the control unit is configured to hold a channel voltage of the first memory subblock constant during the first portion of the read operation.
8. The apparatus of claim 7 , wherein the control unit is further configured to increase a channel voltage of the first memory subblock constant during the second portion of the read operation.
9. A method comprising:
enabling a first select gate drain switch of a first memory subblock and a second select gate drain switch of a second memory subblock during a first portion of a read operation;
increasing a voltage of a control signal associated with the first and second memory subblocks to a first voltage;
disabling the first select gate drain switch of the first memory subblock during a second portion of the read operation; and
increasing the voltage of the control signal to a second voltage during the second portion of the read operation.
10. The method of claim 9 , wherein a channel voltage of the first memory subblock is constant during the first portion of the read operation.
11. The method of claim 10 , wherein the channel voltage of the first memory subblock increases during the second portion of the read operation.
12. The method of claim 9 , wherein enabling the first and second select gate drain switches comprises providing, by a control unit, an active control signal to a gate of the first and second select gate drain switches.
13. The method of claim 12 , wherein disabling the first select gate drain switch comprises providing, by the control unit, an inactive control signal to the gate of the first select gate drain switch.
14. The method of claim 9 , further comprising:
enabling a first select gate source switch of the first and second memory subblocks during the first portion of the read operation.
15. The method of claim 14 , wherein the first select gate drain switch is disabled responsive to determining that an access line associated with the first and second memory subblocks is charged to the first voltage.