Semiconductor memory device and method of manufacturing the same

Abstract

A semiconductor memory device according to an embodiment includes: a substrate; a bit line positioned on the substrate and extending in a first direction; a channel accommodating insulating layer positioned on the substrate, and defining a channel trench exposing the bit line and extending in a second direction crossing the first direction; a channel layer extending along a bottom surface and a side surface of the channel trench and contacting the bit line; a word line positioned in the channel trench and extending in the second direction; a gate insulating layer positioned between the channel layer and the word line; and a capacitor structure positioned on the channel layer and electrically connected to the channel layer, in which the channel layer has a double layer structure of an oxide semiconductor layer and a first graphene layer.