Semiconductor memory device

Abstract

A semiconductor memory device including a substrate including an active pattern that includes a first source/drain region and a second source/drain region; an insulating layer on the substrate; a line structure on the insulating layer and extending in a first direction to cross the active pattern, the line structure penetrating the insulating layer on the first source/drain region and including a bit line electrically connected to the first source/drain region; and a contact spaced apart from the line structure and electrically connected to the second source/drain region, wherein the bit line includes a first portion vertically overlapped with the first source/drain region; and a second portion vertically overlapped with the insulating layer, and wherein a lowermost level of a top surface of the first portion of the bit line is at a level lower than a lowermost level of a top surface of the second portion of the bit line.