Method of fabricating semiconductor device

A method for fabricating a semiconductor device, comprising:

• providing a substrate including a peripheral circuit region and a cell array region;
• forming a peripheral structure on the peripheral circuit region;
• forming a lower insulating layer to cover the peripheral structure and the cell array region, the lower insulating layer having a lower protruding portion on the peripheral structure;
• forming a mold structure on the cell array region, the mold structure including upper sacrificial patterns and insulating patterns that are alternately and repeatedly stacked on the lower insulating layer;
• forming an upper insulating layer to cover the lower protruding portion and the mold structure;
• and
• forming an peripheral contact plugs to penetrate the lower insulating layer and the upper insulating layer.

A method for fabricating a semiconductor device, comprising:

• (a) forming a first insulation layer on a substrate;
• (b) forming a stack on the first insulation layer, the stack including alternating conductive patterns and insulating patterns which are adjacent to a protruding gate structure on the substrate;
• (c) forming a second insulation layer on the stack and the protruding gate structure, an upper surface of the second insulation layer including a protrusion corresponding to the protruding gate structure;
• and
• (d) removing the protrusion of the second insulation layer.