Structure including multiple wire-layers and methods for forming the same

A method for forming a structure including multiple wire-layers, the method comprising steps of:

• preparing an underlying layer;
• providing a plurality of first wires on the underlying layer;
• forming a liner insulating film on the underlying layer provided with the plurality of first wires, so that concave portions are respectively formed between the first wires, which are adjacent to each other, and so that convex portions are respectively formed on the first wires;
• providing a first insulating material on the liner insulating film;
• planarizing a top surface of the first insulating material to form a buried insulating film;
• forming a cap insulating film so as to coat the buried insulating film;
• forming via-holes that pass through the cap insulating film, the buried insulating film, and the liner insulating film so as to reach the first wires;
• filling the via-holes and coating a top surface of the cap insulating film with a second insulating material;
• etching the second insulating material so as to form side walls at side portions of the via-holes and to expose top surfaces of the first wires at bottom portions of the via-holes;
• filling the via-holes with conductive embedded members;
• and
• providing a second wire layer so as to be electrically connected to the first wires via the embedded members;
• wherein a dielectric constant of the first insulating material is lower than that of the liner insulating film and the cap insulating film.