Semiconductor storage device and method of manufacturing semiconductor storage device

A semiconductor storage device comprising:

• a stacked body including a plurality of conductive layers and a plurality of insulating layers alternately stacked;
• and
• a plurality of pillars each including a core material extending in the stacked body in a first direction intersecting a face of each of the plurality of conductive layers, a semiconductor layer covering a side face of the core material, and a multi-layered insulating layer stacked on a side face of the semiconductor layer, the semiconductor layer being crystalline, the multi-layered insulating layer including a charge storage layer, wherein
• the semiconductor layer includes an additive that includes one or more of carbon, nitrogen, oxygen, and fluorine, and
• a ratio of pillars in which a crystal grain boundary appears in the semiconductor layer among the plurality of pillars is less than 2% in a cross section in a direction intersecting the first direction when the cross section positions at a center of the plurality of pillars in the first direction.

A method of manufacturing a semiconductor storage device, the method comprising:

• forming a stacked body including a plurality of first insulating layers and a plurality of second insulating layers alternately stacked;
• forming a plurality of holes extending in the stacked body in a first direction intersecting a face of each of the plurality of first insulating layers;
• forming a multi-layered insulating layer including a charge storage layer and covering respective sidewalls of the plurality of holes;
• forming a first semiconductor layer covering respective sidewalls of the plurality of holes with the multi-layered insulating layer interposed therebetween, the first semiconductor layer being amorphous;
• crystallizing the first semiconductor layer by annealing treatment using metal assist to form a second semiconductor layer, the second semiconductor layer being crystalline;
• filling, with a core material, the plurality of holes surrounded by the second semiconductor layer;
• and
• when the first semiconductor layer is formed, adding an additive that is one or more of carbon, nitrogen, oxygen, and fluorine to the first semiconductor layer closer to the multi-layered insulating layer in a layer thickness direction of the first semiconductor layer.