Semiconductor storage device

A semiconductor storage device, comprising:

• a first conductive layer, a second conductive layer separated from the first conductive layer in a first direction, and a first chalcogen layer provided between the first conductive layer and the second conductive layer;
• a third conductive layer, a fourth conductive layer separated from the third conductive layer in the first direction, and a second chalcogen layer provided between the third conductive layer and the fourth conductive layer;
• and
• a peripheral circuit connected to the first conductive layer and the second conductive layer, wherein
• the third conductive layer and the fourth conductive layer are not connected to the peripheral circuit,
• the second chalcogen layer contains tellurium (Te), and
• when a minimum value and a maximum value of a composition ratio of tellurium in the second chalcogen layer observed along the first direction are a first minimum value and a first maximum value, respectively,
• the first minimum value is observed at a position closer to the third conductive layer than a center position in the first direction of the second chalcogen layer, and
• the first maximum value is observed at a position closer to the fourth conductive layer than the center position in the first direction of the second chalcogen layer.