Non-volatile memory device and method for driving the same
AssigneeSK hynix Inc.
InventorSung Joo Ha
Life of this patent
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Abstract
A non-volatile memory device and a method for driving the same are disclosed. During a precharge operation, the bit line is precharged on the basis of a voltage applied to a common source line. The bit line is precharged or not precharged based on whether or not a selected memory cell is in an erased state or a program state.
Drawings
Claims23
A non-volatile memory device comprising:
- a first memory string including a plurality of non-volatile memory cells coupled between a common source line and a first bit line, the first memory string being one of a plurality of memory strings in the non-volatile memory device;
- a first string selection transistor coupled between the common source line and the first memory string;
- a precharge drive circuit configured to provide a first voltage to a gate terminal of the first string selection transistor and provide a second voltage to the common source line during a precharge operation;
- and
- a controller configured to determine a word line selection voltage having a voltage level sufficient to turn on a memory cell coupled to a selected word line if the memory cell is in a first state but insufficient to turn on the memory cell if the memory cell is in a second state,
- wherein the first string selection transistor provides the second voltage to the first memory string in response to the first voltage in order to precharge the first bit line, and
- wherein the first bit line is precharged if the memory cell is in the first state and not precharged if the memory cell is in the second state.
A method for driving a non-volatile memory device which includes a memory string and a string selection transistor, the memory string including a plurality of non-volatile memory cells provided between a common source line and a bit line, the string selection transistor provided between the memory string and the common source line, wherein each non-volatile memory cell is coupled to a word line, the method comprising:
- providing a first voltage to a gate terminal of the string selection transistor during a precharge operation;
- providing a second voltage to the common source line during the precharge operation;
- determining a word line selection voltage between threshold voltage distribution regions having a voltage level to turn on or turn off a non-volatile memory cell coupled to a selected word line according to whether the non-volatile memory cell is in a first state or a second state;
- applying the word line selection voltage to the selected word line, the selected word line being coupled to one of the non-volatile memory cells;
- and
- precharging the bit line by providing the second voltage to the memory string in response to the first voltage,
- wherein the bit line is precharged if the non-volatile memory cell is in the first state and not precharged if the non-volatile memory cell is in the second state.
A method for precharging a non-volatile memory device having a bit line, a common source line and a memory string that is provided between the bit line and the common source line, the method comprising:
- applying a first voltage to a gate terminal of a string selection transistor, the string selection transistor having a first terminal coupled to the memory string and a second terminal coupled to the common source line;
- applying a second voltage to the second terminal of the string selection transistor via the common source line;
- and
- applying a word line selection voltage to a selected word line coupled to a gate terminal of a memory cell, the word line selection voltage having a voltage level sufficient to turn on the memory cell if the memory cell is in a first state but insufficient to turn on the memory cell if the memory cell is in a second state,
- wherein the bit line is precharged if the memory cell is in the first state and not precharged if the memory cell is in the second state.
Dependencies are inferred from the claim text.