Semiconductor storage element and manufacturing method thereof

A semiconductor storage element comprising:

• a laminated body in which insulating layers and conductive layers are alternately laminated in a first direction;
• a semiconductor layer disposed in the first direction in the laminated body;
• a first insulator disposed in the first direction between the laminated body and the semiconductor layer;
• a second insulator disposed in the first direction between the laminated body and the first insulator;
• a third insulator disposed in the first direction between the laminated body and the second insulator;
• and
• a fourth insulator including a first part and a second part, the first part being disposed between each of the conductive layers and the third insulator, the second part being disposed in a second direction intersecting the first direction between each of the conductive layers and the insulating layer and connected to the first part, wherein
• the first part includes a High-k film, and
• the ratio of heavy hydrogen concentration to light hydrogen concentration in the High-k film is equal to or larger than 10.

A semiconductor storage element manufacturing method comprising:

• sequentially forming a first insulator, a second insulator, a third insulator, and a semiconductor layer, which extend in a first direction, in a second direction intersecting the first direction in a laminated body in which sacrifice layers and insulating layers are alternately laminated in the first direction;
• removing the sacrifice layer and forming a fourth insulator on a surface of a region from which the insulating layer is removed;
• and
• performing spike annealing treatment for a holding time of five seconds or shorter at a treatment temperature of 1000° C. or higher by using heavy hydrogen (D2) gas and heavy water (D2O) to introduce heavy hydrogen (D) into the first insulator, the second insulator, the third insulator, and the fourth insulator.