Semiconductor storage device and method of manufacturing semiconductor storage device

A semiconductor storage device comprising:

• a stack including a plurality of first conductive layers and a plurality of insulating layers, the plurality of first conductive layers and the plurality of insulating layers being alternately stacked one by one in a first direction;
• a columnar body extending in the first direction in the stack;
• and
• a second conductive layer connected to the columnar body,
• wherein the columnar body includes an insulating core, a memory film provided between the plurality of first conductive layers and the insulating core, and a first semiconductor channel provided between the insulating core and the memory film,
• wherein an upper surface of the insulating core is located lower than an upper end of the columnar body in the first direction,
• wherein the second conductive layer has a main body portion and a protrusion, the protrusion protruding from the main body portion toward the upper surface of the insulating core, the protrusion extending in the first direction inside the columnar body, and
• wherein the protrusion is in contact with the first semiconductor channel on a bottom surface or a side surface of the protrusion, the first semiconductor channel includes a first portion with a first width, a second portion with a second width, and a third portion with a third width, the first portion of the first semiconductor channel disposed between the insulating core and the plurality of first conductive layers, the second portion of the first semiconductor channel connected to the protrusion of the second conductive layer, the third portion disposed between the first portion and the second portion in the first direction, the first width narrower than the second width and the third width wider than the second width.