Flash memory reducing program rising time and program method thereof
The present disclosure provides methods and apparatuses for reducing a program voltage rising time. In some embodiments, a flash memory includes a memory cell array including a plurality of memory cells, a target voltage generator configured to adjust a target voltage level of a word line recovery voltage provided to the plurality of memory cells, and a word line voltage controller configured to provide recovery control signals for controlling the target voltage level of the word line recovery voltage. The target voltage generator is further configured to adjust the word line recovery voltage provided to a selected word line to the target voltage level, based on the recovery control signals provided during a word line recovery operation following a program verify operation, and to reduce a program voltage rising time in a program execution operation period of a next program loop by adjusting the target voltage level.
1 . A flash memory, comprising:
a memory cell array comprising a plurality of memory cells;
a target voltage generator configured to adjust a target voltage level of a word line recovery voltage provided to the plurality of memory cells; and
a word line voltage controller configured to provide recovery control signals for controlling the target voltage level of the word line recovery voltage,
wherein the target voltage generator is further configured to:
adjust the word line recovery voltage provided to a selected word line to the target voltage level, based on the recovery control signals provided during a word line recovery operation following a program verify operation;
adjust the target voltage level of the word line recovery voltage during the word line recovery operation; and
reduce a program voltage rising time in a program execution operation period of a next program loop by adjusting the target voltage level, and
wherein a previous program voltage rising time of a previous program loop is greater than the program voltage rising time of the program execution operation period of the next program loop.
2 . The flash memory of claim 1 , wherein the target voltage generator is further configured to:
adjust the target voltage level of the word line recovery voltage, according to a final verify voltage level of the program verify operation.
3 . The flash memory of claim 1 , wherein the target voltage generator is further configured to:
adjust the target voltage level of the word line recovery voltage, according to a height of the selected word line.
4 . The flash memory of claim 1 , wherein the target voltage generator is further configured to:
adjust the target voltage level of the word line recovery voltage, according to program loops.
5 . The flash memory of claim 4 , wherein the target voltage generator is further configured to:
adjust a time for maintaining the target voltage level of the word line recovery voltage, according to the program loops.
6 . The flash memory of claim 1 , wherein the target voltage generator is further configured to:
provide word lines adjacent to the selected word line with at least one of a first voltage and a first supply time of at least one pass voltage; and
provide remaining unselected word lines with at least one of a second voltage and a second supply time of at least another pass voltage,
wherein the first voltage is different from the second voltage,
wherein the first supply time is different from the second supply time.
7 . The flash memory of claim 6 , wherein the target voltage generator is further configured to:
apply a first pass voltage to adjacent word lines during a rising period of the at least another pass voltage provided to the remaining unselected word lines; and
apply a second pass voltage to the adjacent word lines during a maintaining period of the at least another pass voltage provided to the remaining unselected word lines,
wherein the second pass voltage is higher than the first pass voltage.
8 . The flash memory of claim 7 , wherein the second pass voltage is different from the at least another pass voltage provided to the remaining unselected word lines.
9 . The flash memory of claim 1 , wherein the target voltage generator is further configured to:
adjust a first supply time of the word line recovery voltage applied to the selected word line.
10 . The flash memory of claim 9 , wherein the first supply time of the word line recovery voltage of the selected word line occurs at an earlier time point than a second supply time of the word line recovery voltage of remaining unselected word lines.
11 . A program method of a flash memory comprising a memory cell array comprising a plurality of memory cells, the program method comprising:
adjusting a target voltage level of a word line recovery voltage provided to the plurality of memory cells; and
providing recovery control signals for controlling the target voltage level of the word line recovery voltage,
wherein the adjusting the target voltage level comprises:
adjusting the word line recovery voltage provided to a selected word line to the target voltage level, based on the recovery control signals provided during a word line recovery operation following a program verify operation;
adjusting the target voltage level of the word line recovery voltage during the word line recovery operation; and
reducing a program voltage rising time in a program execution operation period of a next program loop by adjusting the target voltage level, and
wherein a previous program voltage rising time of a previous program loop is greater than the program voltage rising time of the program execution operation period of the next program loop.
12 . The program method of claim 11 , wherein the target voltage level of the word line recovery voltage is adjusted according to a final verify voltage level of the program verify operation.
13 . The program method of claim 11 , wherein the target voltage level of the word line recovery voltage is adjusted according to a height of the selected word line.
14 . The program method of claim 11 , wherein the target voltage level of the word line recovery voltage is adjusted according to program loops.
15 . The program method of claim 14 , further comprising adjusting a time for maintaining the target voltage level of the word line recovery voltage according to the program loops.
16 . The program method of claim 11 , further comprising:
providing word lines adjacent to the selected word line with at least one of a first voltage and a first supply time of at least one pass voltage; and
providing remaining unselected word lines with at least one of a second voltage and a second supply time of at least another pass voltage,
wherein the first voltage is different from the second voltage,
wherein the first supply time is different from the second supply time.
17 . The program method of claim 16 , further comprising:
applying a first pass voltage to adjacent word lines during a rising period of the at least another pass voltage provided to the remaining unselected word lines; and
applying a second pass voltage to the adjacent word lines during a maintaining period of the at least another pass voltage provided to the remaining unselected word lines,
wherein the second pass voltage is higher than the first pass voltage.
18 . The program method of claim 17 , wherein the second pass voltage is different from the at least another pass voltage provided to the remaining unselected word lines.
19 . The program method of claim 11 , further comprising adjusting a first supply time of the word line recovery voltage applied to the selected word line.
20 . The program method of claim 19 , wherein the first supply time of the word line recovery voltage of the selected word line occurs at an earlier time point than a second supply time of the word line recovery voltage of remaining unselected word lines.