Nonvolatile semiconductor memory
First Claim
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1. A nonvolatile semiconductor memory comprising:
- a data line;
a first memory cell unit including not only a first memory string in which a plurality of memory cells with charge accumulating regions are electrically connected in series but also first and second select transistors connected to said data line from one end of said first memory string;
a second memory cell unit including not only a second memory string structured similarly to said first memory string but also third and fourth select transistors connected to said data line from one end of said second memory string, said second memory cell unit being adjacent to said first memory cell unit;
a third memory cell unit including not only a third memory string structured similarly to said first memory string but also fifth and sixth select transistors connected to said data line from one end of said third memory string, said third memory cell unit being adjacent to said second memory cell unit;
a first select signal line electrically connected to a control electrode of said first select transistor of said first memory cell unit and to a control electrode of said third select transistor of said second memory cell unit; and
a second select signal line electrically connected to a control electrode of said fourth select transistor of said second memory cell unit and to a control electrode of said sixth select transistor of said third memory cell unit.
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Abstract
In a NAND type flash memory, control electrodes of first select transistors in a plurality memory cell units extending along a data line is integrated to constitute a first select signal line while control electrodes of second select transistor are integrated to constitute a second select signal line. The second select signal line is displaced from the first select signal line by a half pitch.
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Citations
20 Claims
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1. A nonvolatile semiconductor memory comprising:
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a data line; a first memory cell unit including not only a first memory string in which a plurality of memory cells with charge accumulating regions are electrically connected in series but also first and second select transistors connected to said data line from one end of said first memory string; a second memory cell unit including not only a second memory string structured similarly to said first memory string but also third and fourth select transistors connected to said data line from one end of said second memory string, said second memory cell unit being adjacent to said first memory cell unit; a third memory cell unit including not only a third memory string structured similarly to said first memory string but also fifth and sixth select transistors connected to said data line from one end of said third memory string, said third memory cell unit being adjacent to said second memory cell unit; a first select signal line electrically connected to a control electrode of said first select transistor of said first memory cell unit and to a control electrode of said third select transistor of said second memory cell unit; and a second select signal line electrically connected to a control electrode of said fourth select transistor of said second memory cell unit and to a control electrode of said sixth select transistor of said third memory cell unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A nonvolatile semiconductor memory comprising:
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a first memory cell unit including a first memory string to which a plurality of memory cells having charge accumulating regions and placed on a surface of a substrate are electrically connected in series;
a first enhancement type select transistor electrically connected in series to one end of said first memory string; and
a second depression type select transistor electrically connected in series to said first select transistor;a second memory cell unit including a second memory string structured similarly to said first memory string;
a third depression type select transistor electrically connected in series to one end of said second memory string;
a fourth enhancement type select transistor electrically connected in series to said third select transistor, said second memory cell unit being adjacent to said first memory cell unit;a first select signal line connected to said first and third select transistors; a second select signal line connected to said second and fourth select transistors; and a data line extending across said first and second memory cell units, and electrically connected to said second select transistor of said first memory cell unit and said fourth select transistor of said second memory cell unit. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A nonvolatile semiconductor memory comprising:
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a data line; a first memory cell unit including not only a memory string to which a plurality of memory cells having charge accumulating regions are electrically connected in series but also a first enhancement type select transistor, a second depression type select transistor, a third enhancement type select transistor, and a fourth depression type selector, all of which are electrically connected in series to one end of said first memory string; a second memory cell unit configured similarly to said first memory unit, electrically connected in parallel to said data lines, and being adjacent to said first memory cell unit along said data lines; a third memory cell unit including a memory string which is structured similarly to said memory string of said first memory cell unit, and includes a fifth depression type select transistor, a sixth enhancement type select transistor, a seventh depression type select transistor, and an eighth enhancement type select transistors, said third memory cell unit being adjacent to said second memory cell unit along said data line and electrically connected in parallel to said data line; a fourth memory cell unit being adjacent to said third and second memory cell units, extending along said data line, electrically connected to said data line, and structured similarly to said third memory cell unit; a first select signal line electrically connected not only to control electrodes of said first select transistors of said first and second memory cell units but also to control electrodes of said fifth select transistors of said third and fourth memory cell units; a second select signal line electrically connected not only to control electrodes of said second select transistors of said first and second memory cell units but also to control electrodes of said sixth select transistors of said third and fourth memory cell units, said second select signal line extending along said data line with a half pitch displaced from said first select signal line; a third select signal line electrically connected not only to control electrodes of said third select transistors of said first and second memory cell units but also to control electrodes of said seventh select transistors of said third and fourth memory cell units, said second select signal line extending along said data line with a pitch same as that of said first select signal line; and a fourth select signal line electrically connected not only to control electrodes of said fourth select transistors of said first and second memory cell units but also to control electrodes of said eighth select transistors of said third and fourth memory cell units, said fourth select signal line being arranged with a pitch same as that of said second select signal line.
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Specification