a gate structure comprising a gate electrode layer and an interlayer insulation structure which are alternately stacked;

a dielectric structure disposed to contact a sidewall surface of the gate structure; and

a channel layer disposed over a sidewall surface of the dielectric structure,

wherein the interlayer insulation structure comprises a metal-organic framework layer and an inner insulation layer,

wherein the metal-organic frame work layer contacts a surface of the gate electrode layer in a vertical direction, and

wherein the inner insulation layer is spaced apart from the gate electrode layer and fills entire spaces between the metal-organic frame work layer in the vertical direction,

wherein the inner insulation layer comprises at least one of oxide, nitride, and oxynitride.