Manufacturing method of semiconductor device

A method of manufacturing a semiconductor device, comprising:

• providing a semiconductor substrate comprising a first insulation film formed on a top surface thereof and a pad electrode formed on the first insulation film;
• forming on a bottom surface of the semiconductor substrate a hard mask having an opening corresponding to the pad electrode on the top surface;
• forming using the hard mask as an etching mask a via hole that has an undercut around the opening so that a lateral size of the via hole is larger than the opening of the hard mask, part of the first insulation film that covers the pad electrode is exposed in the via hole;
• removing the exposed part of the first insulation film;
• forming a second insulation film on the hard mask and inside the via hole so that the second insulation film comprises an overhung portion extending from a rim of the via hole toward an inside of the via hole;
• etching the second insulation film using the overhanging portion of the second insulation film as a mask to expose the pad electrode at a bottom of the via hole;
• forming in the via hole a through-hole electrode that is electrically connected with the pad electrode;
• and
• cutting the semiconductor substrate to produce a semiconductor die.

A method of manufacturing a semiconductor device, comprising:

• providing a semiconductor substrate comprising a first insulation film formed on a top surface thereof and a pad electrode formed on the first insulation film;
• forming from a bottom surface of the semiconductor substrate a via hole penetrating through the semiconductor substrate to expose part of the first insulation film that covers the pad electrode;
• removing the exposed part of the first insulation film;
• forming a second insulation film on the bottom surface of the semiconductor substrate and inside the via hole;
• forming a metal mask made of a metal on the second insulation film so that an opening of the metal mask corresponds to the via hole;
• etching the second insulation film using the metal mask to expose the pad electrode at a bottom of the via hole;
• removing the metal mask;
• forming in the via hole a through-hole electrode that is electrically connected with the pad electrode;
• and
• cutting the semiconductor substrate to produce a semiconductor die.