Semiconductor memory device and manufacturing method of semiconductor memory device

Abstract

A semiconductor memory device includes a bit line, a common source pattern above the bit line, a channel layer in contact with the common source pattern, the channel layer extending toward the bit line, and a filling insulating layer disposed between the bit line and the common source pattern, the filling insulating layer surrounding a first part of the channel layer. The semiconductor memory device also includes a gate stack structure disposed between the bit line and the filling insulating layer, the gate stack structure surrounding a second part of the channel layer. The semiconductor memory device further includes a first etch stop pattern on a sidewall of the filling insulating layer, a second etch stop pattern between the first etch stop pattern and the filling insulating layer, and a memory pattern between the gate stack structure and the channel layer.