Semiconductor storage device

A semiconductor storage device, comprising:

• a plurality of memory strings, each including first and second memory transistors adjacent to each other;
• a plurality of bit lines connected to the memory strings, respectively;
• a plurality of sense transistors having gates connected to the bit lines, respectively;
• a plurality of first transistors connected between the bit lines and the gates of the sense transistors, respectively;
• and
• a control circuit configured to perform, during a first write sequence, a read operation with respect to the second memory transistors of the memory strings, a program operation with respect to the first memory transistors of the memory strings, and a verify operation with respect to the first memory transistors of the memory strings, in this order, wherein
• during the read operation, the control circuit determines a first part of the second memory transistors having a threshold voltage higher than a predetermined value and a second part of the second memory transistors not having a threshold voltage higher than the predetermined value, and
• during the verify operation, the control circuit turns on the first transistors during a first sense period while one or more of the bit lines connected to the first part are at a first voltage and one or more of the bit lines connected to the second part are at a second voltage lower than the first voltage, and then turns on the first transistors during a second sense period longer than the first sense period while the one or more of the bit lines connected to the first part are at the second voltage and the one or more of the bit lines connected to the second part are at the first voltage.