Semiconductor memory devices and their manufacturing methods

Abstract

This invention provides a semiconductor memory device and a method for manufacturing the same, which can improve the characteristics of a semiconductor layer. The semiconductor memory device of this embodiment includes a stacked body and a columnar portion. The stacked body is a stacked body in a first direction consisting of a plurality of first conductive layers separating insulating layers. The columnar portion extends through the stacked body in the first direction. The columnar portion has a semiconductor layer and a memory film. The semiconductor layer extends through the stacked body in the first direction. The memory film includes a first insulating film, a charge accumulation layer, and a second insulating film disposed between the stacked body and the semiconductor layer. The semiconductor memory device further includes a second conductive layer electrically connected to the semiconductor layer at the end of the columnar portion. At least one grain within the semiconductor layer has a shape that is in contact with the memory film. The semiconductor layer at the end of the columnar portion has a first opening, or a grain boundary exists in the semiconductor layer at the end of the columnar portion.

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