Semiconductor memory devices

Abstract

This invention provides a semiconductor memory device with appropriate ON / OFF characteristics. The semiconductor memory device of this invention comprises: a plurality of conductive layers equally arranged in a first direction; a semiconductor layer extending along the first direction, with its outer peripheral surface facing the plurality of conductive layers, and containing one or more additive elements selected from the group consisting of carbon, nitrogen, oxygen, fluorine, and boron; a first insulating layer extending along the first direction, with its outer peripheral surface surrounded by the semiconductor layer; a charge storage layer disposed between the plurality of conductive layers and the semiconductor layer; and a second insulating layer disposed between the charge storage layer and the semiconductor layer. The semiconductor layer includes: a first region disposed between the first insulating layer and the second insulating layer, containing the additive element; a second region disposed between the first region and the second insulating layer, containing the additive element; and a third region disposed between the first region and the second region. The third region does not contain the additive element, or the average concentration of the additive element in the first and second regions is higher than the average concentration of the additive element in the third region.

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