Semiconductor memory devices and their manufacturing methods

Abstract

This invention provides a semiconductor memory device capable of more appropriately forming a multilayer structure and a method for manufacturing the same. The semiconductor memory device according to this embodiment includes a multilayer body formed by alternately depositing a first conductive layer and a first insulating layer in a first direction. The multilayer body has a first columnar portion, a second columnar portion, and a separation portion. The first columnar portion is disposed in a first region of the multilayer body and includes a first semiconductor portion extending along the first direction within the multilayer body. The second columnar portion is disposed in a second region of the multilayer body, extends along the first direction within the multilayer body, and includes an insulator. The separation portion extends along the first direction and a second direction intersecting the first direction within the multilayer body, separating the first region and the second region. The number of layers in the first columnar portion is different from the number of layers in the second columnar portion and the separation portion. It further includes a first crosslinking portion at a junction portion of the separation portion of adjacent layers. The position of the first crosslinking portion in the first direction is the position in the first direction of the middle portion between the upper and lower ends of the first columnar portion.

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