A semiconductor device includes a first semiconductor layer including a recess region and protrusions defined by the recessed region, first insulating patterns provided on the protrusions and extending to sidewalls of the protrusions, and a second semiconductor layer to fill the recess region and cover the first insulating patterns. The protrusions includes a first group of protrusions spaced apart from each other in a first direction to constitute a row and a second group of protrusions spaced from the first group of protrusions in a second direction intersecting the first direction and spaced from each other in the first direction to constitute a row. The second group of protrusions are shifted from the first group of protrusions in the first direction.