Word-line structure, memory and method of manufacturing the same

Provided is a word-line structure including a substrate, a word line, and an epitaxial pattern. The word line is embedded in the substrate. The word line includes a conductive layer, a barrier layer, an insulating layer, and a gate dielectric layer. The barrier wraps a lower portion of the conductive layer. The insulating layer wraps an upper portion of the conductive layer. The gate dielectric layer surrounds the insulating layer and the barrier layer to electrically isolate the barrier layer and the substrate. The epitaxial pattern is disposed between the insulating layer and the substrate and in contact with the substrate. A memory device including the word-line structure and a method of manufacturing the same are also provided.