NAND flash programming and method of applying read pulse before end of program

A semiconductor storage device comprising:

• a plurality of memory strings each including a plurality of memory cell transistors connected in series, the plurality of memory strings being connected in parallel to one another;
• a plurality of word lines connected to gates of the plurality of memory cell transistors;
• a block including the plurality of memory strings connected to the plurality of word lines in common;
• and
• a control circuit, wherein
• the plurality of word lines include a first word line and a second word line different from the first word line,
• the plurality of memory cell transistors include a first memory cell transistor and a second memory cell transistor, the first memory cell transistor being connected to the first word line, the second memory cell transistor being connected to the second word line,
• the control circuit controls a first write operation and a second write operation, the first write operation being performed on the first memory cell transistor, the second write operation being performed on the second memory cell transistor after the first write operation,
• the first and second write operations include a plurality of loops each including at least a program operation,
• a last loop in the first write operation performs the program operation and does not perform a verify operation and a first voltage application operation that applies a predetermined voltage to the first and second word lines,
• a last loop in the second write operation performs the program operation and the first voltage application operation, and does not perform a verify operation, wherein
• in a first predetermined duration that follows the first write operation and in which no command is input, the control circuit applies a ground voltage to the first and second word lines or sets the first and second word lines to floating states,
• in a second predetermined duration that follows the second write operation and in which no command is input, the control circuit applies the ground voltage to the first and second word lines or sets the first and second word lines to floating states, and then performs a second voltage application operation that applies a predetermined voltage to the first and second word lines, and
• a duration of the first predetermined duration is the same as a duration of the second predetermined duration.

A semiconductor storage device comprising:

• a plurality of memory strings each including a plurality of memory cell transistors connected in series, the plurality of memory strings being connected in parallel to one another;
• a plurality of word lines connected to gates of the plurality of memory cell transistors;
• a block including the plurality of memory strings connected to the plurality of word lines in common;
• and
• a control circuit configured to control a write operation on at least part of the plurality of memory cell transistors, wherein
• the semiconductor storage device is configured to receive a control command related to a first voltage application operation, a write command and an address and perform data writing,
• the write operation is executed in response to reception of the write command and the address,
• the control circuit determines, in response to the control command, whether to perform the first voltage application operation before the write operation ends,
• the first voltage application operation applies a predetermined voltage to the plurality of word lines, and
• when the control command is received, the control circuit omits the first voltage application operation executed before the write operation ends.