Storage device

A storage device comprising:

• a stacked body including gate electrode layers stacked in a first direction, the gate electrode layers including a first gate electrode layer and a second gate electrode layer neighboring the first gate electrode layer in the first direction;
• a semiconductor layer provided in the stacked body and extending in the first direction;
• and
• a gate insulating film including a first region, a second region, and a third region, the second region interposed between the first region and the third region, the first region interposed between the first gate electrode layer and the semiconductor layer, the third region interposed between the second gate electrode layer and the semiconductor layer, and the gate insulating film containing a hafnium oxide,
• wherein the first region contains at least one element selected from a group consisting of silicon (Si), zirconium (Zr), aluminum (Al), yttrium (Y), strontium (Sr), lanthanum (La), samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), ytterbium (Yb), lutetium (Lu), and barium (Ba), and the second region contains or does not contain the at least one element, and
• wherein a first concentration of the at least one element in the first region is higher than a second concentration of the at least one element in the second region.

A storage device comprising:

• a first conductive layer extending in a first direction;
• a second conductive layer extending in the first direction;
• a third conductive layer extending in a second direction intersecting the first direction;
• a first insulating film including a first region, a second region, and a third region, the second region interposed between the first region and the third region, the first region interposed between the first conductive layer and the third conductive layer, the third region interposed between the second conductive layer and the third conductive layer, and the gate insulating film containing a hafnium oxide;
• and
• a second insulating film provided between the first insulating film and the third conductive layer and made of a material different from that of the first insulating film,
• wherein a first thickness of the first region in a third direction from the first conductive layer toward the third conductive layer is smaller than a second thickness of the second region in the third direction.

A storage device comprising:

• a first conductive layer extending in a first direction;
• a second conductive layer extending in the first direction;
• a third conductive layer extending in a second direction intersecting the first direction;
• a first insulating film including a first region, a second region, and a third region, the second region interposed between the first region and the third region, the first region interposed between the first conductive layer and the third conductive layer, the third region interposed between the second conductive layer and the third conductive layer, and the gate insulating film containing a hafnium oxide;
• and
• a second insulating film provided between the first insulating film and the third conductive layer and made of a material different from that of the first insulating film,
• wherein the first region contains at least one element selected from a group consisting of silicon (Si), zirconium (Zr), aluminum (Al), yttrium (Y), strontium (Sr), lanthanum (La), samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), ytterbium (Yb), lutetium (Lu), and barium (Ba), and the second region contains or does not contain the at least one element, and
• wherein a first concentration of the at least one element in the first region is higher than a second concentration of the at least one element in the second region.