Semiconductor device and method of fabricating the same

A semiconductor device, comprising:

• a substrate including a cell array region and a peripheral circuit region;
• stacks on the cell array region of the substrate, the stacks having a first height and extending along a direction;
• a common source structure disposed between adjacent ones of the stacks;
• a peripheral logic structure disposed on the peripheral circuit region of the substrate and having a second height smaller than the first height;
• a plurality of upper interconnection lines disposed on the peripheral logic structure and extending parallel to each other;
• and
• a interconnection structure disposed between the peripheral logic structure and the upper interconnection lines, when viewed in vertical section, and electrically connected to at least two of the upper interconnection lines,
• wherein a top surface of the interconnection structure is positioned between a top surface of the common source structure and bottom surfaces of the upper interconnection lines, when viewed in vertical section.

A method of fabricating a semiconductor device, comprising:

• providing a substrate with a cell array region and a peripheral circuit region;
• forming a plurality of stacks on the cell array region of the substrate, the stacks extending along a direction and defining a cell trench exposing the substrate;
• forming an insulating gap-fill layer on the peripheral circuit region of the substrate to include a first peripheral trench, whose bottom surface is spaced apart from a top surface of the substrate and whose top width is smaller than a top width of the cell trench;
• forming an insulating sidewall spacer in the cell trench and a first insulating spacer in the first peripheral trench, the insulating sidewall spacer exposing the substrate and the first insulating spacer covering side and bottom surfaces of the first peripheral trench;
• and
• forming a common source line filling the cell trench provided with the insulating sidewall spacer and a conductive line filling the first peripheral trench provided with the first insulating spacer.