Semiconductor device including vertical channel pattern and method for fabricating the same

Abstract

A semiconductor device may include a bit line on the substrate, a channel pattern on the bit line and extending in a direction perpendicular to the bit line, a word line intersecting the bit line and spaced apart from the channel pattern, a gate insulating pattern between the channel pattern and the word line, an insulating pattern on the word line, and a landing pad connected to the channel pattern. The gate insulating pattern may include a first gate insulating pattern and a second gate insulating pattern having a first dielectric constant and a second dielectric constant, respectively. The second gate insulating pattern may be between the first gate insulating pattern and the word line. The first and second dielectric constants may be different. A first width of the first gate insulating pattern may be different from a second width of the second gate insulating pattern.