# US 9,437,308 B2 · Nonvolatile semiconductor memory device which performs improved erase operation

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- Number: US 9,437,308 B2
- Document ID: US9437308B2
- Status: Granted
- Kind: B2
- Application number: 14/677,484
- Filed: 2015-04-02
- Published: 2015-07-30
- Granted: 2016-09-06
- Earliest claimed: 2010-08-17
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Jun Nakai; Noboru Shibata
- Web page: https://patentgrep.com/patent/US9437308B2

## CPC

- G11C 16/16: for erasing blocks, e.g. arrays, words, groups
- G11C 16/14: Circuits for erasing electrically, e.g. erase voltage switching circuits
- G11C 16/26: Sensing or reading circuits; Data output circuits
- G11C 16/344: {Arrangements for verifying correct erasure or for detecting overerased cells}
- G11C 16/3445: {Circuits or methods to verify correct erasure of nonvolatile memory cells}
- G11C: STATIC STORES (semiconductor memory devices H10B)

## Abstract

According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control unit. The memory cell array includes a plurality of memory cells arranged in a matrix. The control unit erases data of the memory cells. The control unit interrupts the erase operation of the memory cells and holds an erase condition before the interrupt in accordance with a first command during the erase operation, and resumes the erase operation based on the held erase condition in accordance with a second command.

## Claims

### Claim 1

A nonvolatile semiconductor memory device comprising:
a memory cell array including a plurality of blocks, one of the blocks including a plurality of memory cells; and
a controller configured to perform an erase operation including a first operation and a second operation,
the first operation including supplying a first erase voltage to the selected block,
the controller configured to interrupt the erase operation when the controller receives a first command for interrupting the erase operation, the controller configured to perform the second operation when the controller receives a second command for resuming the erase operation, the second operation including supplying a second erase voltage to the selected block, the second erase voltage being higher than the first erase voltage.

### Claim 2 (depends on 1)

The device according to claim 1, further comprising a first terminal unit configured to receive address data followed by the second command.

### Claim 3 (depends on 1)

The device according to claim 1, wherein the second operation further includes supplying a first verify voltage to the selected block before supplying the second erase voltage to the selected block.

### Claim 4 (depends on 1)

The device according to claim 1, wherein the controller is configured to output a status to an external point when the controller receives a third command for reading the status, the status including a status representing an erase success or failure when the erase operation has been interrupted.

### Claim 5 (depends on 1)

The device according to claim 1, further comprising a second terminal unit configured to output a ready/busy signal.

### Claim 6 (depends on 5)

The device according to claim 5, wherein the second terminal unit outputs a first signal indicating a ready state as the ready/busy signal after receiving the first command.

### Claim 7 (depends on 6)

The device according to claim 6, wherein the second terminal unit outputs a second signal indicating a busy state as the ready/busy signal after receiving the second command.

### Claim 8 (depends on 7)

The device according to claim 7, wherein the controller is configured not to supplying a verify voltage after receiving the first command in the first operation.

### Claim 9 (depends on 1)

The device according to claim 1, wherein the controller is configured to receive a first command during supplying the first erase voltage to the selected block.

### Claim 10 (depends on 8)

The device according to claim 8, wherein the controller is configured to receive a first command during supplying the first erase voltage to the selected block.