Semiconductor devices and methods of manufacturing the same

Abstract

A semiconductor device includes a substrate including a word line trench extending in a first horizontal direction; a gate dielectric layer in the word line trench; a word line extending in the first horizontal direction and in a lower portion of the word line trench on the gate dielectric layer; an insulation capping layer extending in an upper portion of the word line trench on the word line; and a plurality of gate electrodes on the substrate, wherein the word line comprises: a word line lower region extending in the first horizontal direction and including a first gate electrode of the plurality of gate electrodes on the gate dielectric layer; and a word line upper region extending in the first horizontal direction on the word line lower region and including a plurality of second gate electrodes of the plurality of gate electrodes and the first gate electrode.