SEMICONDUCTOR DEVICE

A semiconductor device includes: a substrate including a cell array area, a periphery circuit area, and an interface area; bit lines arranged in the cell array area and extending in a first horizontal direction; a mold insulating layer arranged on the bit lines and including openings extending in a second horizontal direction; channel layers respectively arranged on the bit lines in each of the openings; word lines respectively arranged on the channel layers and extending in the second horizontal direction from the cell array area to the interface area, the word lines including a first word line on a first sidewall of each opening of the mold insulating layer and a second word line on a second sidewall of the opening; and a trimming insulating block arranged in the interface area and connected to an end of the first word line and an end of the second word line.